Service Manual

Open Circuit Axial Piston Pumps
Series 45 J Frame

www.danfoss.com

Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps

Revision history

Table of revisions
Date

ChangedRev

November 2023

Changed document number from 'AX00000041' to 'AX152886481532'

0306

September 2016

Added displacement limiter adjustments

0203

March 2016

add Fan Drive Control

0202

September 2014

add ETL and angle sensor

BA

December 2012

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Series 45 J Frame Open Circuit Axial Piston Pumps
Contents
Introduction
Overview..............................................................................................................................................................................................5
Safety precautions............................................................................................................................................................................5
Unintended machine movement..........................................................................................................................................5
Flammable cleaning solvents................................................................................................................................................. 5
Fluid under pressure.................................................................................................................................................................. 5
Personal safety............................................................................................................................................................................. 5
Symbols used in Danfoss literature............................................................................................................................................6
General description......................................................................................................................................................................... 6
System circuit.....................................................................................................................................................................................7
Technical Specifications
General specifications.....................................................................................................................................................................9
Hydraulic parameters................................................................................................................................................................... 10
Inlet pressure..............................................................................................................................................................................10
Pressure compensator valve setting..................................................................................................................................10
Case pressure............................................................................................................................................................................. 10
Hydraulic fluid ...........................................................................................................................................................................10
Temperature range.................................................................................................................................................................. 10
Fluid viscosity.............................................................................................................................................................................10
Filtration ......................................................................................................................................................................................10
Features
Auxiliary mounting pads............................................................................................................................................................. 11
Input shafts.......................................................................................................................................................................................11
Control options...............................................................................................................................................................................11
Operation.....................................................................................................................................................................................11
PC control.................................................................................................................................................................................... 12
LS control.....................................................................................................................................................................................12
Electric Proportional Controls.............................................................................................................................................. 13
PLUS+1® Compliance......................................................................................................................................................... 13
Electric Proportional Control Principle........................................................................................................................ 13
Electric On/Off Controls..........................................................................................................................................................14
PLUS+1® Compliance......................................................................................................................................................... 14
Electric On-Off Control Principle....................................................................................................................................14
Fan Drive Control (FDC)..........................................................................................................................................................14
PLUS+1 Compliance...........................................................................................................................................................14
Fan Drive Control Principle .............................................................................................................................................15
S45 pump with integrated FDC control schematic.................................................................................................15
Electronic Torque Limiting Controls (ETL)....................................................................................................................... 16
Pressure Measurement
Required tools................................................................................................................................................................................. 18
Port locations and gauge installation.....................................................................................................................................18
Initial Start-Up Procedures
General...............................................................................................................................................................................................19Start-up procedure........................................................................................................................................................................ 19
J Frame pumps with radial endcap.................................................................................................................................... 19
Fluid and Filter Maintenance
Recommendations........................................................................................................................................................................ 20
Troubleshooting
Excessive noise and/or vibration..............................................................................................................................................21
Actuator response is sluggish....................................................................................................................................................21
System operating hot...................................................................................................................................................................21
Low pump output flow................................................................................................................................................................22
Pressure or flow instability..........................................................................................................................................................22
System pressure not reaching PC setting............................................................................................................................. 23High inlet vacuum..........................................................................................................................................................................23© Danfoss | November 2023

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Series 45 J Frame Open Circuit Axial Piston Pumps
Contents
Adjustments
PC control..........................................................................................................................................................................................24
FDC Control......................................................................................................................................................................................25
Control Adjustment................................................................................................................................................................. 26
FDC Control Data...................................................................................................................................................................... 26
Fan Drive Control pressure setting guidelines...............................................................................................................26
LS control.......................................................................................................................................................................................... 27
Displacement limiter.....................................................................................................................................................................28
Minor Repair
Shaft seal replacement.................................................................................................................................................................30
Auxiliary pads.................................................................................................................................................................................. 31
LS and PC Controls.........................................................................................................................................................................32
Electric Controls..............................................................................................................................................................................35
Electronic Torque Limiting Control......................................................................................................................................... 36
Fan Drive Control........................................................................................................................................................................... 37
Angle Sensor....................................................................................................................................................................................39
Servo Control Orifice.....................................................................................................................................................................40
Servo Control Orifice Disassembly..................................................................................................................................... 40
Servo Control Orifice Reassembly.......................................................................................................................................41
Plug and fitting sizes and torques........................................................................................................................................... 41

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Series 45 J Frame Open Circuit Axial Piston Pumps
Introduction
Overview
This manual includes information for the installation, maintenance, and minor repair of the Series 45
frame J open circuit axial piston pumps. The manual includes a description of the units and theirindividual components, troubleshooting information, and minor repair procedures. Performing
installation, maintenance, and minor repair of Series 45 J frame axial piston pumps according to theprocedures in this manual will not affect your warranty.
Performing minor repairs requires the unit to be removed from the vehicle/machine. Thoroughly clean
the unit before beginning maintenance, or repair activities. Since dirt and contamination are the greatest
enemies of any type of hydraulic equipment, follow cleanliness requirements strictly. This is especially
important when changing the system filter and when removing hoses or plumbing.
A worldwide network of Danfoss Authorized Service Centers (ASCs) is available for major repairs. Major
repairs require the removal of the unit’s endcap, which voids the warranty unless done by an ASC.
Danfoss ASCs are trained by the factory and certified on a regular basis. You can locate your nearest ASC
using the distributor locator at www.Danfoss.com
Safety precautions
Always consider safety precautions before beginning a service procedure. Protect yourself and othersfrom injury. Take these general precautions whenever servicing a hydraulic system.
Unintended machine movement

W Warning
Unintended movement of the machine or mechanism may cause injury to the technician or bystanders.
To protect against unintended movement, secure the machine or disable / disconnect the mechanism
while servicing.
Flammable cleaning solvents

W Warning
Some cleaning solvents are flammable. To avoid possible fire, do not use cleaning solvents in an area
where a source of ignition may be present.
Fluid under pressure

W Warning
Escaping hydraulic fluid under pressure can have sufficient force to penetrate your skin causing serious
injury and/or infection. This fluid may also be hot enough to cause burns. Use caution when dealing withhydraulic fluid under pressure. Relieve pressure in the system before removing hoses, fittings, gauges, orcomponents. Never use your hand or any other body part to check for leaks in a pressurized line. Seek
medical attention immediately if you are cut by hydraulic fluid.
Personal safety

W Warning
Protect yourself from injury. Use proper safety equipment, including safety glasses, at all times.

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Series 45 J Frame Open Circuit Axial Piston Pumps
Introduction
Symbols used in Danfoss literature
WARNING may result in injury

Tip, helpful suggestion

CAUTION may result in damage to product orproperty

Lubricate with hydraulic fluid

Reusable part

Apply grease / petroleum jelly

Non-reusable part, use a new part

Apply locking compoundNon-removable item

Inspect for wear or damage

Option - either part may exist

Clean area or part

Superseded - parts are not interchangeable

Be careful not to scratch or damage

Measurement required

Note correct orientation

Flatness specification

Mark orientation for reinstallation

Parallelism specification

Torque specification

External hex head

Press in - press fit

Internal hex head

Pull out with tool – press fit

Torx head

Cover splines with installation sleeve

O-ring boss port

Pressure measurement/gauge location or
specification

The symbols above appear in the illustrations and text of this manual. They are intended to communicate
helpful information at the point where it is most useful to the reader. In most instances, the appearanceof the symbol itself denotes its meaning. The legend above defines each symbol and explains its purpose.
General description
Danfoss Series 45 J frame open circuit piston pumps convert input torque into hydraulic power.
Rotational force is transmitted through the input shaft to the cylinder block. The input shaft is supported
by tapered roller bearings at the front and rear of the pump and is splined into the cylinder block . A lipseal at the front end of the pump prevents leakage where the shaft exits the pump housing. The spinning
cylinder block contains nine reciprocating pistons. Each piston has a brass slipper connected at one end
by a ball joint. The slippers are held to the swashplate by the spring retainer and block spring. The block
spring also holds the cylinder block to the valve plate. The reciprocating movement of the pistons occurs
as the slippers slide against the inclined swashplate during rotation. Via the valve plate, one half of thecylinder block is connected to pump inlet and the other half to pump outlet. As each piston cycles in andout of its bore, fluid is drawn from the inlet and displaced to the outlet thereby imparting power into thesystem circuit. A small amount of fluid is allowed to “leak” from the cylinder block/valve plate and slipper/
swashplate interfaces for lubrication and cooling. Case drain ports are provided to return this fluid to thereservoir.
The volume of fluid displaced into the system circuit is controlled by the angle of the swashplate. The
swashplate is forced into an inclined position (into stroke) by the bias spring. The servo piston opposes
the action of the bias spring forcing the swashplate out of stroke when hydraulic pressure in the control
circuit rises above the spring force.

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Series 45 J Frame Open Circuit Axial Piston Pumps
Introduction
The pump control, by varying the pressure at the servo piston, controls the displacement of fluid in thesystem circuit. Controls designed for Pressure Compensation (PC) or Load Sensing (LS) are available. For adetailed description of control operation, refer to Control options.
Pump and control sectional view
LS control(attached to endcap)
LS spool

LS adjustment
PC adjustment

PC spool

Bias spring
Servo piston
PistonSlipper

Shaft seal

Valve plate

Input shaft

BlockspringTaperedrollerbearing

Cylinder block

TaperedrollerbearingSlipper retainer

Swashplate
P104 362

System circuit
The pump receives fluid directly from the reservoir through the inlet line. A screen placed in the inlet
protects the pump from large contaminants. The output of the pump is directed to a PVG-32 multisection load sensing directional control valve which directs fluid to the actuators in the system. Fluid
returning from the system is cooled by a heat exchanger and cleaned by a filter before returning to thereservoir.
The speed of the actuators in the system depends on the volume of fluid being provided by the pump.
The operating pressure varies depending on actuator load, but is limited to an adjustable maximum
setting by the PC section of the pump control and by a system relief valve integrated into the sidemodule of the PVG valve.
The position of the PVG valve sets the demand for flow in the system and communicates this to thepump control by means of a hydraulic signal (load sense signal). The pump will provide as much flow to
the system as it demands1 while limiting the maximum pressure. Therefore flow and pressure in thesystem are compensated to meet requirements.

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Introduction
Pictorial circuit diagram
J Frame Series 45
open circuit axial
piston pump wit hload sensing control

Double-a cting cylinder

PVG 32
multi-se ctionload
sensing
controlvalve

Bi-directiona lgear mo tor

System p ressu re
Servo pressu re
Rese rvoir

FilterHeat exchange r

Actuator pressure
Load sense p ressu re
Actuator retu rn

P104 366E

Suction / case d rain /system retu rn

Full available flow is a function of pump displacement, operating speed, and efficiency. Refer to Series 45
Axial Piston Open Circuit Pumps Technical Information, 520L0676 for details.

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Series 45 J Frame Open Circuit Axial Piston Pumps
Technical Specifications
General specifications
Features and options
Feature

Unit

Model
J45B

J51B

J60B

J65C

J75C

Maximum Displacement

cm³ [in³]

45 [2.75]]

51 [3.11]

60 [3.66]

65 [3.97]

75 [4.58]

Flow at rated speed (theoretical)l/min[US gal/min]

126.0[33.3]

137.7[36.4]

156.0[41.2]

162.6[42.9]

180[47.5]

Input torque at maximum displacement(theoretical)

N•m/bar[lbf•in/1000 psi]

0.716
[436.9]0.811[495.1]0.956[583.6]1.035[631.4]

1.193[728.1]Mass moment of inertia of internal rotating
components

kg•m²[slug•ft²]

0.00455[0.00336]

0.00455[0.00336]

0.00455[0.00336]

0.00433[0.00319]

0.00433[0.00319]

Weightkg [lb]23.13 [51]Axial ports
Radial ports

26.65 [58.8]

Rotation

Clockwise, Counterclockwise

Mounting

2 bolt SAE-B, 4 bolt SAE-C

Auxiliary mounting

SAE-A, SAE-B, SAE-BB, SAE-C

System ports (type)

SAE R-ring boss. 4-bolt split flange

System ports (location)

Axial, Radial

Control types

PC, Remote PC, LS, LS with internal bleed

ShaftsSplined

13-tooth, 14-tooth, 15-tooth

TaperedØ 31.75 mm [1.25 in], 1:8 taper

Straight

Ø 31.75 mm [1.25 in]

Displacement limiters

Available

Ratings
RatingInput speed¹

minimum

Units

Model
J45B

J51B

J60B

J65C

J75C

min-1 (rpm)

500

500

500

500

500

2800

2700

2600

2500

2400

continuous

3360

3240

3120

3000

2880

Working pressure

maximum

maximumbar [psi]

310 [4495]

310 [4495]

310 [4495]

260 [3770]

260 [3770]

External shaft loads

External moment (Me)N•m [lbf•in]

226 [2000]

226 [2000]

226 [2000]

226 [2000]

226 [2000]

Thrust in (Tin), out (Tout)N [lbf]

2200 [495]2200 [495]2200 [495]2200 [495]2200 [495]at 140 bar [2030 psi]

B10 hours

29 71229 71229 71210 75510 755at 210 bar [3045 psi]

6834

6834

6834

2474

2474

at 260 bar [3770 psi]

3151

3151

3151

—

—

at 310 bar [4495 psi]

1666

1666

1666

—

—

Bearing life

Mounting flange load
moments

Vibratory (continuous)
Shock (max)N•m [lbf•in]

SAE-C: 1500 [14 000], SAE-B: 735 [6500]
SAE-C: 5600 [50 000], SAE-B: 2600 [23 000]

1. Continuous input speeds are valid at 1 bar absolute [0 in HG vac] inlet pressure. Maximum input speeds
require changing the inlet pressure or reducing pump displacement..

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Technical Specifications
Hydraulic parameters
Inlet pressure
Minimum pressure, continuous = 0.8 bar absolute [6.7 inches Hg vac.] (at reduced maximum pumpspeed)
Minimum pressure, cold start = 0.5 bar absolute [15.1 inches Hg vac.]
Pressure compensator valve setting
Minimum: 100 bar [1450 psi]
Maximum: 310 bar [3770 psi] (depending on displacement)
For more information, refer to Series 45 J Frame Axial Piston Open Circuit Pumps Technical Information,
520L0676.
Case pressure
Maximum continuous: 0.5 bar [7 psi] Above inlet
Intermittent: 2 bar [29 psi] Cold start
Hydraulic fluid
Refer to Danfoss publication Fluids and Filtration BLN-9887 or BC152886484524. For information on
biodegradable fluids refer to Biodegradable Hydraulic Fluids, 520L0465. See Fluid and filter maintenancefor recommended fluid and filter change intervals.
Temperature range
Hydraulic fluid viscosity must be maintained within the prescribed limits.
Intermittent (cold start): - 40° C [- 40° F]
Continuous: 82° C [180° F]
Maximum: 104° C [220° F]
As measured at the hottest point in the system, e.g. drain line.
Fluid viscosity
Viscosity limits
Ratingν continuous

ν intermittent

mm2/s (cSt) [SUS]
minimum

9 [58]

maximum

110 [500]

minimum

6.4 [47]

maximum (cold start)

1000 [4700]

Filtration
Required cleanliness level: ISO 4406 Class 18/13 or better. Refer to Danfoss publications Fluids andFiltration BLN-9887 or BC152886484524 and Design Guidelines for
Selecting and Maintaining the Required Hydraulic Fluid Cleanliness 520L0465. See Fluid and filter
maintenance for recommended fluid and filter change intervals.

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Series 45 J Frame Open Circuit Axial Piston Pumps
Features
Auxiliary mounting pads
Auxiliary mounting pads are available for all radial ported Series 45 pumps. These pads are typically used
for mounting auxiliary hydraulic pumps.
Since the auxiliary pad operates under case pressure, an O-ring must be used to seal the auxiliary pump
mounting flange to the pad. The drive coupling is lubricated by oil from the main pump case. For details
refer to Series 45 J Frame Axial Piston Open Circuit Pumps Technical Information, 520L0676.
Auxiliary pad options

P104 361

Input shafts
Series 45 J frame pumps are available with a variety of splined, straight keyed, and tapered end shafts. For
information on shafts refer to Series 45 J Frame Axial Piston Open Circuit Pumps Technical Information,
520L0676.
Control options
The Series 45 Frames J have three possible general control options, a Load Sensing (LS) control withPressure Compensator (PC), a PC only control, or an electric control.
Operation
The bias spring (1) pushes against the servo piston (2) which pulls the swashplate (3) to max angle
causing the pump to stroke. Internal pressure on the servo piston acts against the bias spring to reduce
the swashplate angle causing the pump to destroke. Swashplate angle determines pump outlet flow. The
pump control, depending on conditions in the system circuit, sets swashplate angle by metering systempressure to the servo piston.
Cross-section pump2

1

3

P104 360

Bias spring and servo piston set swashplate position© Danfoss | November 2023

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Features
PC control
The PC control design maintains a constant pressure in the hydraulic circuit as flow varies. The PC control
modulates pump flow accordingly to maintain system pressure at the PC setting as the PC adjusting plug(4) and spring (5) defines.
When system pressure, acting on the non-spring end of the PC spool (6), overcomes the force of the PC
spring, the spool shifts porting system pressure to the servo piston and the swashplate angle decreases.
When system pressure drops below the PC setting, the PC spring shifts the spool in the opposite
direction connecting the servo piston to pump case and the swashplate angle increases. The swashplate
is maintained at whatever angle is required to keep system pressure at the PC setting.
Cross-section PC control
46

5P104 049

PC spool shifts to port system pressure to servo piston
LS control
The LS control design matches pump flow with system demand. The LS control senses the flow demandof the system as a pressure drop across the External Control Valve (ECV). As the ECV opens and closes, thepressure delta across the valve changes. When opening, the delta decreases. When closing, the delta
increases. The LS control then increases or decreases pump flow to the system until the pressure delta
becomes equal to the LS setting as defined by the LS adjusting plug (7) and spring (8).
Typical load-sensing control valve
Loadpressur e

Returnpressur e
Tank

Load sensepressur e

Systempressur e

P101 665E

Pressure drop across external control valve defines system demand
Cross-section LS control

Spring Spring
LS spring
guide
Spool
LS adjusting
Plug
plug
PC adjusting
plug
Plug
Spool

SpringSpring (PC heavy)
guide

P104 051

LS spool shifts to port system pressure to servo piston

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Series 45 J Frame Open Circuit Axial Piston Pumps
Features
The LS control consists of two spool valves that connect the servo piston either to pump case or systempressure. The PC spool (6) controls the pressure-compensating function of the control as previously
described. The LS spool (9) controls the load-sensing function. The PC spool has priority over the LS spool.
Through internal porting, system pressure (upstream of ECV) is applied to the non-spring end of the LS
spool, and through hydraulic line connected at port X, LS pressure (downstream of ECV) is applied to thespring end. This arrangement allows the LS spool to act on the delta between system pressure and LS
pressure. The LS spring sets the threshold of operation (LS setting).
Because the swashplate is biased to maximum angle, the pump attempts to deliver full flow to thehydraulic system. When the flow being delivered exceeds demand, the pressure delta across the ECV isgreat enough to overcome spring force and shift the LS spool porting system pressure to the servo
piston. The pump de-strokes reducing flow until the delta across the ECV becomes equal to the LS
setting. When flow being delivered is less than demand, the delta across the ECV drops below the LS
setting and the LS spring shifts the spool connecting the servo piston to pump case. The pump strokes
increasing flow until the delta across the ECV becomes equal to the LS setting.
When the external control valve is placed in neutral, it connects the LS signal line to drain. With no LS
pressure acting on the non-spring end of the LS spool, the pump adjusts stroke to whatever position
necessary to maintain system pressure at the LS setting. The pump is now in standby mode.
Because of the series arrangement of the LS and PC spools, the PC spool will override the LS spool. If at
any time system pressure reaches the PC setting, the PC spool will shift blocking the passage thatconnects the LS spool with the servo piston and porting system pressure to the servo piston causing thepump to destroke.
Electric Proportional Controls

PLUS+1® Compliance
All Series 45 Electric controls have met and passed the Danfoss PLUS+1® compliance standard testing,and as such, this Series 45 control is PLUS+1® compliant. PLUS+1® compliance blocks are available on the
Danfoss website, within the PLUS+1 Guide section.

Electric Proportional Control Principle
The Electric Proportional Control consists of a proportional solenoid integrated into a Remote Pressure
Compensated control. This control allows the pump to be operated at any pressure limit between the
Load Sense and Pressure Compensation settings by varying the current sent to the solenoid.

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Features
Electric On/Off Controls

PLUS+1® Compliance
All Series 45 Electric controls have met and passed the Danfoss PLUS+1® compliance standard testing,and as such, this Series 45 control is PLUS+1® compliant. PLUS+1® compliance blocks are available on the
Danfoss website, within the PLUS+1 Guide section.

Electric On-Off Control Principle
The Electric On/Off Control consists of an On/Off solenoid integrated into a Remote Pressure
Compensated control. This control allows the pump to be operated at either the Load Sense pressure
setting when “On”, or the Pressure Compensation pressure setting when “Off”.

Fan Drive Control (FDC)

PLUS+1 Compliance
All Series 45 Electric controls have met and passed the Danfoss PLUS+1 compliance standard testing, andas such, this Series 45 control is PLUS+1 compliant. PLUS+1 compliance blocks (software) are available on
the Danfoss website, within the PLUS+1 Guide section.

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Series 45 J Frame Open Circuit Axial Piston Pumps
Features
Fan Drive Control Principle
The Fan Drive Control is a unique electrically actuated pressure control solution that consists of anormally closed proportional solenoid and one dual diameter spool sliding in the control housing.
System pressure acts on an area between the two spool diameters of the spool lands. This hydraulic force
is balanced with forces of springs and the solenoid when the spool is in the metering position. When no
current is sent to the solenoid it operates the pump at or below the PC setting which is adjusted
mechanically with the adjustor screw and lock nut. Increasing the control current proportionally reduces
the pump's outlet pressure until a minimum standby pressure is reached.
Control Block 12V and 24V

The minimum system pressure is given by swashplate moments of the pump and by servo systemleakages which produce a pressure drop across the control. In addition, fan motor type and fan inertia
impact minimum system pressure.
The Normally Closed Fan Drive Control coupled with a microprocessor allows the pump to operate at an
infinite range of operating pressures between a minimum system pressure and PC setting.

W Warning
A relief valve is required to be installed in the pump outlet for additional system protection. Failure to
install a relief valve may lead to system damage and/or injury.

W Warning
The Fan Drive Control is intended for fan drive systems only! Use in other systems could result in systemcomponent damage or unintended machine movement. The Fan Drive Control is not intended to serveat the primary system pressure relief. Loss of the input signal to this control will cause the pump to
produce maximum flow.

S45 pump with integrated FDC control schematic
LegendGain
Orifice

B

B
S
L1, L2= Outlet= Inlet= Case drain

Choke
Orifice

L2
S© Danfoss | November 2023

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Series 45 J Frame Open Circuit Axial Piston Pumps
Features
Electronic Torque Limiting Controls (ETL)

PLUS+1 Compliance
All controls for this product have met and passed the Danfoss PLUS+1® compliance standard testing, andas such, this product control is PLUS+1® Compliant. PLUS+1® compliance blocks (software) are available
on the Danfoss website, |ETL load senseconnection port

Electric Torque Limiting Control Principle
The Electronic Torque Limiting control consists of a normally closed proportional relief valve (PRV)
integrated into a Pressure Compensated/Load Sensing control. This control operates as a PC/LS control,with the additional ability to limit load sense pressure using the integrated PRV by varying the current tothe solenoid. When combined with an angle sensor, this control allows for a PC/LS control with electronic
torque limiting.
J-frame pump with integrated ETL control
X(ETL Signal
Port)

B
M2

S

P108779

Pump torque consumption is a function of pump outlet pressure, pump displacement, and pumpmechanical efficiency. When pump mechanical efficiency is considered constant, the pump torque canbe limited when pump displacement is known and pump pressure is controlled. As pump displacement
increases, the pump outlet pressure can be limited using the PRV to result in a constant torque limit.
Pump outlet pressure is equal to the load sense pressure, which is limited with the PRV, plus the marginpressure setting of the pump.
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Series 45 J Frame Open Circuit Axial Piston Pumps
Features© Danfoss | November 2023

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Pressure Measurement
Required tools
The service procedures described in this manual can be performed using common mechanic’s handtools. Special tools, if required are shown. Calibrate pressure gauges frequently to ensure accuracy. Use
snubbers to protect gauges.
Port locations and gauge installation
The illustration below shows gauge port locations. Recommended pressure gauges and fittings are in thetable.
J Frame pumps with radial endcap do not have an M1 system pressure port. Measure system pressure in
the hydraulic system as close to the pump as possible.
Gauge and port information
Port

PurposeRange of gauge

Fitting

M1

System pressure

0-300 bar [0-5000 psi]

9/16 - 18 O-ring fitting

L1, L2

Case drain port

0-10 bar [0-100 psi]

7/8 - 14 O-ring fittingX

LS signal

0-300 bar [0-5000 psi]

7/16 - 20 O-ring fitting (teeinto LS signal line)

Gauge port locations
x

M1

L1

L2
P104 364

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Series 45 J Frame Open Circuit Axial Piston Pumps
Initial Start-Up Procedures
GeneralFollow this procedure when starting-up a new Series 45 installation or when restarting an installation inwhich the pump has been removed.

W Warning
Unintended movement of the machine or mechanism may cause injury to the technician or bystanders.
To protect against unintended movement, secure the machine or disable/disconnect the mechanism
while servicing.
Prior to installing the pump, inspect for damage incurred during shipping. Make certain all systemcomponents (reservoir, hoses, valves, fittings, heat exchanger, etc.) are clean prior to filling with fluid.
Start-up procedure
1. Connect the pump to the prime mover. Ensure that pump shaft is properly aligned with the shaft ofthe prime mover.

C Caution
Incorrect shaft alignment may result in damage to drive shaft, bearings, or seal which can cause
external oil leakage.
2. Fill the reservoir with recommended hydraulic fluid. Always filter fluid through a 10 micron filter
pouring into the reservoir. Never reuse hydraulic fluid.
3. Fill the main pump housing with clean hydraulic fluid. Pour filtered oil directly into the upper mostcase drain port.
4. Fill the inlet line leading from the pump to the reservoir. Check the inlet line for properly tightened
fittings and be certain it is free of restrictions and air leaks.
5. To ensure the pump stays filled with oil, install the case drain line in the upper most case drain port.
6. Install a gauge at the system pressure gauge port to monitor system pressure during start up.
Follow recommendations in the vehicle/machine operator’s manual for prime mover start up
procedures.
7. While watching the pressure gauge installed at the system pressure gauge port, jog the prime moveror run at the lowest possible speed until system pressure builds to normal levels (minimum 11 bar[160 psi]). Once system pressure is established, increase to full operating speed. If system pressure is
not maintained, shut down the prime mover, determine cause, and take corrective action. Refer tothe Troubleshooting chapter.
8. Operate the hydraulic system for at least fifteen minutes under light load conditions.
9. Check and adjust control settings as necessary after installation. Refer to the Adjustments chapter.
10. Shut down the prime mover and remove the pressure gauge. Replace the plug at the system pressuregauge port.
11. Check the fluid level in the reservoir; add clean filtered fluid if necessary.
The pump is now ready for operation.
J Frame pumps with radial endcap
J Frame pumps with radial endcap do not have an M1 system pressure port. Measure system pressure in
the hydraulic system as close to the pump as possible.

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Fluid and Filter Maintenance
Recommendations
To ensure optimum life of Series 45 products, perform regular maintenance of the fluid and filter.
Contaminated fluid is the main cause of unit failure. Take care to maintain fluid cleanliness whenservicing.
Check the reservoir daily for proper fluid level, the presence of water, and rancid fluid odor. Water in thefluid may be noted by a cloudy or milky appearance or free water in the bottom of the reservoir. Rancid
odor indicates the fluid has been exposed to excessive heat. Change the fluid immediately if these
conditions occur. Correct the problem immediately.
Change the fluid and filter per the vehicle/machine manufacturer’s recommendations or at theseintervals:
Change the fluid more frequently if it becomes contaminated with foreign matter (dirt, water, grease,etc.) or if the fluid is subjected to temperature levels greater that the recommended maximum.
Dispose of used hydraulic fluid properly. Never reuse hydraulic fluid.
Change filters whenever the fluid is changed or when the filter indicator shows that it is necessary tochange the filter. Replace all fluid lost during filter change.
Fluid and filter change interval

20 | © Danfoss | November 2023

Reservoir type

Maximum change interval

Sealed2000 hours

Breather

500 hours

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Troubleshooting
Excessive noise and/or vibration
Item

Description

ActionCheck fluid level in reservoir.

Insufficient hydraulic fluid causes cavitation.

Fill the reservoir to proper level.

Check for air in system.

Air in system causes noisy, erratic control.

Purge air and tighten fittings. Check inlet forleaks.

Check pump inlet pressure/vacuum.

Improper inlet conditions cause erratic behavior
and low output flow.

Correct pump inlet pressure/vacuum conditions.
Refer to the Hydraulic Parameters topic.

Inspect shaft couplings.

A loose or incorrect shaft coupling causes
excessive noise and/or vibration.

Repair or replace coupling and ensure that
correct coupling is used.

Check shaft alignment.

Misaligned shafts create excessive noise and/or
vibration.

Correct shaft misalignment.

Hydraulic fluid viscosity above acceptable limits.

Hydraulic fluid viscosity above acceptable limits
or low fluid temperature will not allow the pump
to fill or control to operate properly.

Allow system to warm up before operating, oruse fluid with the appropriate viscosity grade for
expected operating temperatures. See Hydraulic
Fluids and Lubricants Technical Information
Manual, BC152886484524.

Item

Description

ActionCheck external system relief valve setting.

Low external relief valve setting slows down
system.

Adjust external relief valve setting following
manufacturer’s recommendations. External relief
setting must be above PC setting to operateproperly.

Check PC and LS control setting.

Low PC setting prevents the pump from
Adjust PC and LS setting. Refer to theachieving full stroke. Low LS setting limits output Adjustments chapter.
flow.

Check LS control signal pressures.

Incorrect LS signal will not allow pump to
operate correctly.

Inspect system to ensure that proper LS signaltransmit to pump.

Internal system leaks.

Worn internal parts don’t allow the pump to
operate properly.

Refer to Authorized Service Center for required
repair.

Hydraulic fluid viscosity above acceptable limits.

Hydraulic fluid viscosity above acceptable limits
or low fluid temperature will not allow the pump
to fill or control to operate properly.

Allow system to warm up before operation or sue
fluid with the appropriate viscosity grade for
expected operating temperatures. See Hydraulic
Fluids and Lubricants Technical Information
Manual, BC152886484524.

Check external system valving.

Malfunctioning valving may not allow system torespond properly.

Repair or replace system valving as required.

Check pump case pressure.

High case pressure causes the system to besluggish.

Correct case drain line restrictions.

Check pump inlet pressure/vacuum.

High inlet vacuum causes low output flow.

Correct inlet pressure conditions.

Item

Description

ActionCheck fluid level in reservoir.

Insufficient volume of hydraulic fluid will notmeet cooling demands of system.

Fill reservoir to proper level. Verify proper size ofreservoir.

Inspect heat exchanger. Check air flow and input
air temperature for the heat exchanger.

Insufficient air flow, high input air temperature,or undersized heat exchanges will not meetcooling demands of the system.

Clean, repair, or replace heat exchanger as
required. Verify proper size of heat exchanger.

Actuator response is sluggish

System operating hot© Danfoss | November 2023

AX152886481532en-000306 | 21

Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Troubleshooting
Item

Description

ActionCheck external system relief valve setting.

Fluid passing through relief valve adds heat tosystem.

Adjust external system relief valve setting
following manufacturer’s recommendations.
External relief valve setting must be above PC
setting for proper operation.

Check pump inlet pressure/vacuum.

High inlet vacuum adds heat to system.

Correct inlet pressure/vacuum conditions.

Item

Description

ActionCheck fluid level in reservoir.

Insufficient hydraulic fluid will limit output flow
and cause internal damage to pump.

Fill the reservoir to proper level.

Hydraulic fluid viscosity above acceptable limits.

Fluid viscosity above acceptable limits or low
fluid temperature will not allow the pump to fillor control to operate properly.

Allow system to warm up before operating, oruse fluid with the appropriate viscosity grade for
expected operating temperatures. See Hydraulic
Fluids and Lubricants Technical Information
Manual, BC152886484524.

Check external system relief valve setting.

Eternal relief valve set below PC setting causes
low output flow.

Adjust external relief valve following
manufacturer’s recommendation. External relief
valve setting must be above PC setting tooperate properly.

Check PC and LS control setting.

Low PC setting prevents the pump fromachieving full stroke.

Adjust PC and LS setting. Refer to the
Adjustments chapter.

Check pump inlet pressure/vacuum.

High inlet vacuum causes low output flow.

Correct inlet pressure conditions.

Check input speed.

Low input speeds decrease flow.

Adjust input speed.

Check pump rotation.

Incorrect rotational configuration causes low
flow.

Use pump with appropriate rotational
configuration.

Item

Description

ActionCheck for air in system.

Air in system causes erratic operation.

Activate PC allowing system to bleed air. Check
inlet line for leaks and eliminate source of air
ingression.

Check control spools.

Sticking control spools cause erratic operation.

Inspect spools for free movement in bore. Cleanor replace.

Check LS setting.

Low LS setting may cause instability.

Adjust LS setting to proper level. See the
Adjustments chapter.

Check LS signal line.

Blocked LS signal line interferes with proper LS
operation.

Remove blockage.

Check external relief valve and PC setting.

Insufficient pressure differential between PC
setting and external relief valve.

Adjust external relief valve or PC control settings
to appropriate level. Relief valve setting must be
above PC setting to operate properly.

Check external relief valve.

Chattering external relief valve may cause
unstable feedback to pump control.

Adjust or replace relief valve.

Low pump output flow

Pressure or flow instability

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Series 45 J Frame Open Circuit Axial Piston Pumps
Troubleshooting
System pressure not reaching PC setting
Item

Description

ActionCheck PC control setting.

System pressure will not rise above PC setting.

Adjust PC to appropriate setting. Refer to the
Adjustments chapter.

Check external relief valve.

External relief valve setting below PC setting
presents pressure compensation.

Adjust external relief valve according to
manufacturer’s recommendations. External relief
valve must be set above PC setting to operateproperly.

Inspect PC control spring.

Broken, damaged, or missing spring will cause
erratic operation.

Replace the spring as required.

Inspect PC spool for wear.

Wear of PC spool causes internal leakage in thecontrol.

Replace the spool as required.

Inspect PC spool for proper orientation.

Improper orientation results in poor operation.

Correct orientation of spool.

Check PC control for contamination.

Contamination may interfere with movement of
the PC spool.

Clean PC control components, take appropriate
action to eliminate contamination.

High inlet vacuum

C Caution
High inlet vacuum causes cavitation which can damage internal pump components.
Item

Description

ActionCheck fluid temperature.

Low temperature increases viscosity. High fluid
viscosity causes high inlet vacuum.

Allow system to warm up before operating.

Inspect inlet screen.

Blocked or restricted inlet screen causes highinlet vacuum.

Clean screen/remove blockage.

Check inlet piping.

Too many fittings, bends, or long piping causes
high inlet vacuum.

Eliminate fittings to make path more direct.

Hydraulic fluid viscosity above acceptable limits.

High fluid viscosity causes high inlet vacuum.

Select fluid with appropriate viscosity for
expected operating temperature. See Hydraulic
Fluids and Lubricants Technical Information
Manual, BC152886484524.

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Adjustments
PC control
PC setting is indicated in the pump model code. Refer to the Series 45 J Frame Open Circuit Axial Piston
Pumps Technical Information Manual, BC152886483703, for more information.
Before performing adjustments, read Pressure measurement.
1. Install a pressure gauge in port M1 to measure system pressure. Install a pressure gauge in case drain
port L1 or L2 to measure case pressure.

W Warning
Escaping hydraulic fluid under pressure can have sufficient force to penetrate your skin causing
serious injury and/or infection. Relieve pressure in the system before removing hoses, fittings,
gauges, or components.
Unintended movement of the machine or mechanism may cause injury to the technician or
bystanders. To protect against unintended movement, secure the machine or disable/disconnect themechanism while servicing.

C Caution
Contamination can damage internal components and void the manufacturer’s warranty. Take
precautions to ensure system cleanliness when removing and reinstalling system lines.
2. Start the prime mover and allow fluid to reach normal operating temperature. Operate a hydraulicfunction to its full extension, loading the pump at maximum pressure and zero flow.
3. Loosen the PC set screw and turn the PC adjusting plug until the desired setting is indicated on thepressure gauge at port M1. Clockwise rotation increases pressure, counterclockwise rotation
decreases; approximate gain 42 bar [610 psi] per turn.
P C setting is referenced to case pressure. Subtract case pressure from system pressure to computethe actual setting.
If the pressure does not increase, an external system relief valve may require adjustment. External
system relief valve must be set above the PC setting for proper operation.
4. While holding the position of the PC adjusting plug, torque the PC set screw to 7.5 - 10.8 N•m [5.5 - 8
lbf•ft].
5. Stop the prime mover, remove the pressure gauges, and return the system to its normal operating
configuration.
PC control adjustment
Gauge port M1
0 - 300 bar [0 - 4351 psi]
9/16-28
34-68 N•m [25-50 lbf•ft]

PC set screw
0 - 300 bar [0 - 4351 psi]
9/16-28
34-68 N•m [25-50 lbf•ft]
PC adjusting plug

Case drain port L1
0 - 300 bar [0 - 4351 psi]
9/16-28
34-68 N•m [25-50 lbf•ft]

0 - 300 bar [0 - 4351 psi]
9/16-28
34-68 N•m [25-50 lbf•ft]

P104 365E

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Series 45 J Frame Open Circuit Axial Piston Pumps
Adjustments
Pressure change
J FrameControl option

PC adjustment

LS adjustment

LS, LD, LB, LE, PC, RP

42 bar/rev [609 PSI/rev]

17.2 bar/rev [250 PSI/rev]

BB, BC, BP, BS

36 bar/rev [534 PSI/rev]

AB, AC, AD, AJ, AS

8.5 bar/rev [123 PSI/rev]

FDC Control
FDC setting is indicated in the pump model code. Refer to the Series 45 Open Circuit Axial Piston Pumps
Technical Information Manual, BC152886483703, for more information.
1. Install a pressure gauge in port M1 to measure system pressure. Install a pressure gauge in case drain
port L1 or L2 to measure case pressure.

W Warning
Escaping hydraulic fluid under pressure can have sufficient force to penetrate your skin causing
serious injury and/or infection. Relieve pressure in the system before removing hoses, fittings,
gauges, or components.
Unintended movement of the machine or mechanism may cause injury to the technician or
bystanders. To protect against unintended movement, secure the machine or disable/disconnect themechanism while servicing.

C Caution
Contamination can damage internal components and void the manufacturer’s warranty. Take
precautions to ensure system cleanliness when removing and reinstalling system lines.
2. For more details see also pictorial instruction for FDC PC pressure setting (below).
3. Start the test with the PC adjustment screw turned in 3 revolutions from ‘0’ thread engagement. (PCadjuster fully released - hard stop).
FDC Pressure ranges: 100 bar – 310 bar• Low pressure spring set: 100-210 bar‒ 3 screw turns from ‘0’ thread engagement, PC pressure is adjusted about 140 bar ± 10 bar(based on spring free length)‒ ‘0’ thread engagement is equal to about 80-100 bar (based on spring free length)•High pressure spring set: 220-310 bar‒ 3 screw turns from ‘0’ thread engagement, PC pressure is adjusted about 240 bar ± 10 bar(based on spring free length)‒ ‘0’ thread engagement is is equal to about 180-200 bar (based on spring free length)

4. Disconnect Fan Drive Control signal wire from control. Start the prime mover (or vehicle engine) at
maximal allowed speed value and allow fluid to reach normal operating temperature. With thecontrol’s signal wire disconnected, the fan drive pump will operate at the pressure value related tothe prime mover (vehicle engine) speed value.
5. Loosen the lock nut and turn the PC adjusting screw until the desired the pressure delta between
gauge at port M1 and gauge at port L1 or L2 is indicated. Clockwise rotation increases pressure
setting, counterclockwise rotation decreases; approximate gain 19.1 bar [277 psi] per turn. (PCsett.=p_B – p_case where p_B = outlet pressure and p_case = case pressure ).

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Adjustments
Control Adjustment

FDC Control Data
Item

Description

Wrench Size

Pressure

TorqueM1

Gauge port

1/4 inch internal hex

0-400 bar [0-5801 psi]

24 Nm [17.7 lbf•ft]

L1

Case drain port

3/8 inch internal hex

0-10 bar [0-100 psi]

95 Nm [70.0 lbf•ft]

Lock Nut

-

12 mm

-

8.5 Nm [6.3 lbf•ft]

Adjusting Screw-

3 mm internal hex--

Fan Drive Control pressure setting guidelines

1. Design your system’s fan trim speed to be reached 5 bar below the PC setting• The PC function should not regulate maximum fan speed (maximum system pressure) in a normal
duty cycle (iMax > i > iThreshold)
2. This allows the Fan Drive Control’s PC setting to fulfill its safety functionality without altering normal
fan operation

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Series 45 J Frame Open Circuit Axial Piston Pumps
Adjustments••

The fan trim speed should be reached at Threshold current
Refer to the model order code or the designation on your pump’s nametag for your PC setting
3. RDM integral SCR or customer installed system pressure reliefs should have 15 bar minimum
separation from PC setting• This is done to prevent possible ‘talking’ between the pumps ‘PC’ function and any other systemreliefs• Fans should be rated to operate intermittently at the System Relief Valve setting

LS control
The LS setting is indicated in the pump model code. Refer to the Series 45 J Frame Open Circuit Axial
Piston Pumps Technical Information Manual, BC152886483703, for more information.
If the pressure does not increase, an external system relief valve may require adjustment. External systemrelief valve must be set above the PC setting for proper operation.
Before performing adjustments, read Pressure measurement.
1. Install a pressure gauge in port M1 to measure system pressure. Install a pressure gauge in drain port
L1 or L2 to measure case pressure. Tee-in a gauge to the LS/remote PC signal line (port X).

W Warning
Escaping hydraulic fluid under pressure can have sufficient force to penetrate your skin causing
serious injury and/or infection. Relieve pressure in the system before removing hoses, fittings,
gauges, or components.
Unintended movement of the machine or mechanism may cause injury to the technician or
bystanders. To protect against unintended movement, secure the machine or disable/disconnect themechanism while servicing.

C Caution
Contamination can damage internal components and void the manufacturer’s warranty. Take
precautions to ensure system cleanliness when removing and reinstalling system lines.
2. Start the prime mover and allow fluid to reach normal operating temperature. Slowly operate ahydraulic function that will demand approximately half flow from the pump, but keep systempressure below the PC set point.
3. Loosen the LS set screw. While watching the pressure gauges, turn the LS adjusting plug until thedesired pressure differential between port M1 and port X is achieved. Clockwise rotation increases
the setting, counterclockwise rotation will decrease it; approximate gain = 17 bar [250 psi] per turn.
The LS setting is a differential pressure. Subtract pilot pressure at port X from system pressure at port
M1 to compute the actual setting.
4. While holding the position of the LS adjusting plug, torque the LS set screw to 7.5 - 10.8 N•m [5.5-8
lbf•ft].
5. Operate a hydraulic function to its full extension loading the pump at maximum pressure and zeroflow.
6. Loosen the PC set screw and turn the PC adjusting plug until the desired setting is indicated on thepressure gauge at port M1. Clockwise rotation increases pressure, counterclockwise rotation
decreases it; approximate gain = 42 bar [610 psi] per turn.
PC setting is referenced to case pressure. Subtract case pressure from system pressure to computethe actual setting.
7. While holding the position of the PC adjusting plug, torque the PC set screw to 7.5 - 10.8 N•m [5.5-8
lbf•ft].

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Adjustments
8. Stop the prime mover, remove the pressure gauges, and return the system to its normal operating
configuration.
LS control adjustment
Gauge port M1

LS/ remote PC signal port X

0 - 300 bar [0 - 4351 psi]
9/16-28
34-68 N•m [25-50 lbf•ft]

LS set screw
0 - 300 bar [0 - 4351 psi]
9/16-28
7.5-10.8 N•m [5.5-8 lbf•ft]
LS adjusting plug

Case drain port L1
0 - 300 bar [0 - 4351 psi]
9/16-28
34-68 N•m [25-50 lbf•ft]

0 - 300 bar [0 - 4351 psi]
9/16-28
34-68 N•m [25-50 lbf•ft]
P104 367E

Displacement limiter
J Frame open circuit pumps are available with an optional adjustable displacement limiter. Thisadjustable stop limits the pump’s maximum displacement.
Setting range
J45B

8.4 to 45 cm³ [0.51 to 2.75 in³]

J51B

13.7 to 51 cm³ [0.84 to 3.11 in³]

J60B

16.8 to 60 cm³ [1.03 to 3.66 in³]

J65B

25.4 to 65 cm³ [1.55 to 3.97 in³]

J75B

28.4 to 75 cm³ [1.73 to 4.58 in³]

Displacement per turnJ45B

6.2 cm³/rev [0.38 in³/rev]

J51B

6.2 cm³/rev [0.38 in³/rev]

J60B

6.2 cm³/rev [0.38 in³/rev]

J65B

7.2 cm³/rev [0.44 in³/rev]

J75B

7.2 cm³/rev [0.44 in³/rev]

Displacement limiter cross-section

P106 727E

Displacement limiters are only available for endcap options V and W.

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Series 45 J Frame Open Circuit Axial Piston Pumps
Adjustments
241.65[9.5] 207.12[8.2]

162.54[6.4]

167.72
[6.6]

146.5
[5.8]

P106 728E
Third-angle
projec tion
mm [in]© Danfoss | November 2023

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Minor Repair
Shaft seal replacement
The Series 45 open circuit variable pumps use a lip-type shaft seal. You can replace this seal withoutmajor disassembly of the unit. Replacing the shaft seal requires removing the pump from the machine.
1. Using the appropriate snap-ring pliers, remove the retaining ring (K010) from the housing.
2. Remove the shaft seal (K020) from the bore in the pump housing and discard.

C Caution
Don’t damage the pump housing or shaft.
Remove second seal if pump is so equipped. See illustration below.
3. Puncture the face of the seal with a packing hook, or use a slide-hammer type puller to remove theseal.
Shaft seal and retaining ring
K010
K020

E101 187

4. Inspect the pump housing and new seal for damage. Inspect the sealing area on the shaft for rust,
wear, or contamination. Polish the sealing area on the shaft if necessary.
5. Lubricate the lip of the new shaft seal with clean hydraulic fluid. Place a protective sleeve over theshaft end to prevent damage to the seal during installation.
6. Keeping the seal perpendicular to the shaft, press the new seal into the housing just far enough toclear the retaining ring groove. Install seal with the cupped side toward the shaft bearing. Do notdamage the seal during installation.

C CautionPremature bearing failure can result if the shaft seal contacts the shaft bearing.
Press the seal into the housing only far enough to clear the retaining ring groove.
Install second seal if pump is so equipped. See illustration below.
7. Using the appropriate snap ring pliers, install the seal retaining ring.

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Series 45 J Frame Open Circuit Axial Piston Pumps
Minor Repair
8. Remove the installation sleeve.
Double seal and retaining ring
K010
K020
K020

E108 672E

Auxiliary pads
You may install auxiliary mounting pads on pumps equipped with through-drive radial ported endcaps.
Follow these steps to either remove, replace, or exchange auxiliary mounting pads.
1. Remove the screws (J130), retaining the cover plate (J110) or auxiliary pump (not shown). Remove theshipping cover or auxiliary pump and its seal (J120).
2. Remove the drive coupling (J140) if present.
3. Remove the 4 screws (J100) retaining the pad adapter (J080) to the endcap. Discard the pad adapter
O-ring (J090) if present. Also discard the J095 O-ring.
Auxiliary mounting pads
J095
J090

J080

J120

J140

J110
8 mm

J100

J095
J090

48.5 - 61 N•m[35 - 45 lbf•ft]

J080
J095

J140

J130

J090

3/4 inch

J110

J130
9 /16 inch
38 - 50 N•m[27 - 37 lbf•ft]© Danfoss | November 2023

J095

J080

J120

91 - 111 N•m[67 - 82 lbf•ft]

J140
J120
J110

J100
8 mm

J085

48.5 - 61 N•m[35 - 45 lbf•ft]

E101 256

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Minor Repair
4. Lubricate new O-ring (J090) with petroleum jelly. Install the pad adapter to the endcap.
5. Install the 4 screws (J100 ) and torque to 48.5 - 61 N•m [35 - 45 lbf•ft].
6. Install the drive coupling (J140) if present.
7. Install shipping cover or auxiliary pump with seal (J120).

C Caution
Shipping cover is intended only to retain coupling during shipment and storage. Do not operate
pump with coupling and shipping cover installed.
8. Install the screws (J130) and torque to 94 - 115 N•m [67 - 82 lbf•ft]. If you have an auxiliary A pad,install the screws (J130) and torque to 37 - 50 N•m [27 - 37 lbf•ft].
LS and PC Controls
Disassembly
1. Remove the 4 screws (C300) holding the control housing onto the endcap.
2. Remove the control and discard the 4 interface O-rings (C200).
3. Remove the PC set screw (C102), PC adjusting plug (C138), O-ring (C138A), springs (C134, C135), andseat (C133). Discard the O-ring.
4. Remove the plug (C103), O-ring (C103A), and PC spool (C132) from the control housing. Discard the
O-ring. Note orientation of the spool for reassembly.
For PC only controls, skip steps 5 through 7
5. Remove the plug (C105) and O-ring (C105A), or the plug (C106) and O-ring (C106A). Discard the Oring (C105A or C106A).
6. Remove the LS set screw (C102), LS adjusting plug (C118), O-ring (C118A), back‑up rings (C118B),
springs (C114, C115), and seat (C113). Discard the O-ring and backup rings.

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Series 45 J Frame Open Circuit Axial Piston Pumps
Minor Repair
7. Remove the plug (C104), O-ring (C104A), and LS spool (C112) from the control housing; discard the Oring. Note orientation of the spool for reassembly.
Control assembly

12 N•m
[9 lbf•ft]
12 N•m
[9 lbf•ft]

12 N•m
[9 lbf•ft]
6 N•m[5 lbf•ft]

49 N•m[7 lbf•ft]

12 N•m
[9 lbf•ft]

LS control shown; parts C104 through C106 and C112 through C118 are not used on PC control
Inspection
1. Inspect the adjusting plugs for wear at the tips and where they contact the seat; replace as necessary.
2. Inspect the springs and spring guides for wear or damage; replace as necessary.
3. Carefully inspect the spools. Ensure the sealing lands are free of nicks and scratches. Check the ends
that contact the spring guides for wear. Replace spools as necessary.
4. Inspect the control housing for damage. Check the spool bores for excessive wear.
5. Clean all parts and lubricate spools, springs, guides, and new O-rings with clean hydraulic fluid.
Reassembly
1. Install the PC spool (C132), spherical end first, into the PC bore. Using a new O-ring (C103A), install theplug (C103). Torque the plug (C103) to 12 N•m [9 lbf•ft].
2. Place the two PC springs (C134, C135) onto the spring guide (C133) and install into the PC bore. Placea new O-ring (C138A) onto the PC adjusting screw and thread it into the PC bore until flush, thenmake another full turn. Install and torque the PC set screw (C102) to 9 N•m [7 lbf•ft].
For PC only controls, skip steps 3 through 5.
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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Minor Repair
3. Install the LS spool (C112), spherical end first, into the LS bore. Using a new O-ring (C105A or C106A),
install the plug (C105 or C106). Torque the plug (C105 or C106) to 12 N•m [9 lbf•ft].
4. Using a new O-ring (C104A), install the plug (C104). Torque the plug to 12 N•m [9 lbf•ft].
5. Place the two LS springs (C114, C115) onto the spring guide (C113) and install into the LS bore. Placea new O-ring (C118A) and back-up rings (C118B) onto the LS adjusting screw and thread it into the LSbore until flush, then make another full turn. Install and torque the LS set screw (C102) to 9 N•m [7lbf•ft].
6. Using petroleum jelly to retain them, install 4 new interface O-rings (C200) in the recesses on thecontrol housing.
7. Install the control assembly onto the endcap using the 4 screws (C300). Torque the screws to 6 N•m [5lbf•ft]. Torque screws in a criss-cross pattern and re-torque the first screw to ensure proper torqueretention.
8. Check and adjust the control setting. See Adjustments section.
Control assembly

12 N•m
[9 lbf•ft]
12 N•m
[9 lbf•ft]

12 N•m
[9 lbf•ft]
6 N•m[5 lbf•ft]

49 N•m[7 lbf•ft]

12 N•m
[9 lbf•ft]

LS control shown; parts C104 through C106 and C112 through C118 are not used on PC control

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Minor Repair
Electric Controls
Disassembly
1. Remove four screws (C300).
2. Remove the control and discard the four O-rings (C200).
3. Remove set screws (C102), PC adjusting plug (C138) with O-ring (C138A), springs (C134, C135), andseat (C133). Discard the O-ring if it is damaged.
4. Remove plug (C103). Remove PC spool (C132). Note orientation of the spool for reassembly.
5. Remove plug (G030), and orifice (G020).
6. Remove LS adjusting plug (C118), springs (C114, C115), and seat (C113).
7. Remove plug (C104), and spool (C112). Note the orientation of the spool for reassembly.
8. Remove four screws (C151). Remove the manifold (C152) and discard the two interface O-rings(C154).
9. For electric proportional controls only:
Remove the electric control manifold drain orifice (C149).
10. Remove plug (C153). Remove the cartridge valve nut (C125), electric solenoid (C155), and cartridge
valve (C150) from the electric control manifold.
Control assembly
C103
C125

C104
C132

C300

C112

C155
C102

C150
C149
C152

C154
G030
G020
C200

C151
C133
C113
C115

C135

C153
C114

C134
C138A

C118

P108 668E
C138

Inspection
1. Inspect the adjusting plugs for wear at the tips and where they contact the springs; replace asnecessary.
2. Inspect the springs and spring guides for wear or damage; replace as necessary.
3. Carefully inspect the spools. Ensure the sealing lands are free of nicks and scratches. Check the ends
that contact the spring guides for wear. Replace spools as necessary.
4. Inspect the control housing for damage. Check the spool bores for excessive wear.
5. Remove debris from orifices if necessary. Ensure the servo control orifice backup plug is clean, andremove debris if necessary.
6. Clean all parts and lubricate spools, springs, guides and new O-rings with clean hydraulic fluid.
© Danfoss | November 2023

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Minor Repair
Reassembly
1. Install the servo control orifice (G020), and torque to 2.7 N•m [24 in•lb]. Then install the orifice backup
plug (G030), and torque to 2.7 N•m [24 in•lb].
2. Install the PC spool (C132), spherical end first, into the PC bore. Install plug (C103). Torque the plug to
12 N•m [8.9 lbf•ft].
3. Place the two PC springs (C134, C135) onto the spring guide (C133) and install into the PC bore. Placea new O-ring (C138A) onto the PC adjusting screw (C138) and thread it into the PC bore until flush,
then make another full turn. Install and torque the PC set screw (C102) to 9.6 N•m [7.1 lbf•ft].
4. Install the LS spool (C112), spherical end first, into the LS bore.
5. Install plug (C104). Torque the plug to 12 N•m [8.9 lbf•ft].
6. Place the two LS springs (C114, C115) onto the spring guide (C113) and install into the LS bore.
Thread adjusting screw (C118) into the LS bore until flush, then make another full turn. Install andtorque the LS set screw (C102) to 9.6 N•m [7.1 lbf•ft].
7. Install the electric control manifold drain orifice (C149) and torque to 2.7 N•m [24 in•lb].
8. Install the cartridge valve (C150) into the electric control manifold (C152). Torque to 27.7 N•m [20.4lbf•ft]. DO NOT OVERTORQUE the cartridge valve.
9. Install the electric solenoid (C155), and solenoid coil nut (C125). Torque to 8.7 N•m [6.4 lbf•ft].
10. Install plug (C153). Torque the plug to 12 N•m [8.9 lbf•ft].
11. Using petroleum jelly to retain them, install the two interface O-rings (C154) in the recesses on theelectric control manifold.
12. Install the manifold assembly onto the control housing using four screws (C151). Torque the screws to
6.4 N•m [4.7 lbf•ft]. Torque the screws in a criss-cross pattern and re-torque the first screw to ensure
proper torque retention.
13. Using petroleum jelly to retain them, install the four interface O-rings (C200) in the recesses on thecontrol housing.
14. Install the control assembly onto the endcap using the four screws (C300). Torque the screws to 6.4
N•m [4.7 lbf•ft]. Torque screws in a criss-cross pattern and re-torque the first screw to ensure proper
torque retention.
15. Check and adjust the control setting. See Adjustments section.
Electronic Torque Limiting Control

RepairDisassembly, inspection and reassembly steps are the same as the steps in the previous topic (ElectricControls). This includes repair of the spools and plugs.
The solenoid (C155), nut (QC125), and O-rings (QC120) for the valve are available as separate repair
parts. The valve is only available as a complete assembly (QC150).
If it is necessary to remove the orifice (H020), use a 3 mm internal hex wrench. Torque it to 2.7 Nm [24in-lb] when it is installed in the manifold.

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Minor Repair
C300

QC125
C154
C149

C155

QC150

QC120
*C200

C152
C151

* Included in overhaul seal kit Q210

H020
C153
P108790

Item

Description

Wrench size

Torque

C149

Orifice

3 mm internal hex

2.7 Nm [24 in-lb]

C151

ScrewsC152

Manifold

-

-

C153

Plug

5 mm internal hex

12 Nm [8.9 lbf-ft]

C154

O-ring--

C155

Solenoid

-

-

C200

O-rings

-

-

C300

Screws

QC120

O-rings

QC125

Nut

8.7 Nm [6.4 lbf-ft]

QC150

Valve assembly

27.7 Nm [20.4 lbf-ft]

H020

Manifold orifice

6.4 Nm [4.7 lbf-ft]

6.4 Nm [4.7 lbf-ft]

3 mm internal hex

2.7 Nm [24 in-lb}

Fan Drive Control
Disassembly
Use the wrench sizes and torques listed in the table.
1. Remove four screws (C300).
2. Remove the control and discard the 4 interface O-rings (C200).
3. Remove the coil plastic nut (QC125 ) Remove the coil.
Remember the correct coil connector orientation.
4. Remove the solenoid cartridge (C120). Remove O-ring (QC120).
5. Remove spring (C124) and spring guide (C123).
6. Remove the pressure limiter adjuster (C128).
7. Remove spring (C125) and spool (C122).

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Minor Repair
8. Remove plug (C107) and plug (C129).
9. Remove gain orifice (H030).
10. Remove servo control orifice (G020).
QC125
QC130

Right coil orientation
QC135
C300

Left coil orientation

C124
C123

C107

C120
*QC120

C122

C129
H030

C125
C128B
C128A
C128C

G020

C128

* Included in overhaul seal kit*C200

P109024

Item

Description

Wrench size

TorqueG020

Servo control orifice

3 mm internal hex

2.7 N•m [2 lbf•ft]

H030

Gain orifice

2,5 mm internal hex

2.7 N•m [2 lbf•ft]

C129

Plug 5/16"

1/8“ internal hex

6.2 N•m [4.67 lbf•ft]

C107

Plug 7/16"

3/16" internal hex

13.7 N•m [9.9 lbf•ft]

C128C

Nut 9/16"

17 mm exter hex

23.7 N•m [17.5 lbf•ft]

C120

Solenoid cartridge

17 mm exter hex

25.75 N•m [19 lbf•ft]

QC125

Coil plastic nut

26 mm 12 pt socket

3.5 N•m [2 lbf•ft]

C300

Screws4 mm internal hex

6.5 N•m [4.75 lbf•ft]

Inspection
1. Inspect the pressure limiter for wear. Check for contamination and damage to the O-rings, replace ifnecessary.
2. Inspect the control housing for damage. Check the spool bores for excessive wear. Remove debris
from orifices if necessary.
3. Carefully inspect the spool. Ensure the sealing lands are free of nicks , burrs and scratches. Check theends that contact the spring guides for wear. Replace the spool if necessary.
4. Check the spool for free (smooth) movement in housing bore.
5. Check the orifices (H030 and G020) for contamination, and for cavitation damage.
6. Check the solenoid cartridge for damage, bending, free pin movement.
7. Check the coil for damage Check the plastic plug for contamination.
8. Check the coil connector for contamination or overheat marks, deformation, connector pins are notdamaged or bent, or missing. Replace the coil if necessary.
9. Check the control o-rings for damage, or cracks and replace if necessary.
10. Clean and lubricate all spools, bores, and seals with a light coating of hydraulic oil.

38 | © Danfoss | November 2023

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Minor Repair
Reassembly
1. Install the servo control orifice (G020). Install the gain orifice (H030).
2. Install plugs (C129) and (C107).
3. Install spool (C122) spherical end first, into the spool bore. Install spring (C125).
4. Install the pressure limiter adjuster (C128).
5. Install the spring guide (C123) and spring (C124). Ensure the spring guide is properly seated on thespools spherical head.
6. Install the solenoid cartridge with its O-ring.
7. Install the coil and O-rings. Ensure that the O-rings are correctly installed. Ensure the coil connector isin right orientation.
8. Install the coil plastic nut (QC125 ).
Use the proper wrench, do not damage the plastic nut.
9. Using petroleum jelly to retain them, install the four interface O-rings (C200) in the recesses on thecontrol housing.
10. Install the control assembly onto the endcap using four screws (C300). Torque screws in a criss-crosspattern and re-torque the first screw to ensure proper torque retention.
Angle Sensor

Removal
1. Remove the four sensor housing screws (K190), sensor housing (K260), and sensor housing O-ring(K170).
2. Remove two locating dowels (K180).
3. Remove two magnet carrier screws (K110) and discard. Remove magnet carrier (K100) from pumpswashplate through housing.
Screws (K110) must be discarded after disassembly. Used magnet carrier screws may loosen and leadto premature failure. Ensure that new screws with locking compound are utilized.
During O-ring removal from sensor housing, be careful not to damage or scratch seal area .

K100
K110 K180

K170
K260
K190

Right side
P108789© Danfoss | November 2023

AX152886481532en-000306 | 39

Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Minor Repair
Item

Description

Wrench size

TorqueK100

Magnet carrier

K110

Carrier screws-

4.5 Nm [3.35 lbf ft]

K170

O-ring--K180

Locating dowels

-

K190

ScrewsK260

Housing-

5.9 Nm [4.35 lbf ft]--

Inspection
1. Carefully examine the angle sensor housing for mechanical damages, cracks, or scratched surfaces.
2. Check the angle sensor connector for breaks, pin deformation, or contamination.
3. Check sensor wiring for heat damage, scuffing/chafing, or kinks.
4. Check sensor seal area for contamination and surface damage
5. Check magnet carrier for cracks , deformations, wearing, and for contamination with magnetic
particles

W Warning
A thorough inspection with the angle sensor removed is a strong indicator of pump and hydraulicsystem contamination and filtration quality.
Reassembly
1. Using new magnet carrier screws with locking compound (K110) install the magnet carrier (K100) topump swashplate through the housing. Torque the screws to 4.5 Nm [3.3 lbf-ft].

W Warning
Used magnet carrier screws may loosen and lead to premature failure. Ensure that new screws withlocking compound are utilized.
2. Install the locating dowels (K180) into the dowel holes.
3. Lubricate new O-ring (K170) with petroleum jelly. Install the O-ring to the angle sensor housing(K260) first.
4. Install angle sensor housing (K260) with O-ring (K170) to housing with 4 screws (K190) and torque to
5.9 Nm [4.4 lbf-ft].
Servo Control Orifice
Servo Control Orifice Disassembly
1. Remove four screws (C300).
2. Remove the control and discard the four O-rings (C200).
3. Remove PC plug (C103), and PC spool (C132) from the control housing.
Note the orientation of the spool for reassembly.

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Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Minor Repair
4. Remove backup plug (G030), and orifice (G020).
Control assembly
C103
C132
C300

G030
G020
C200
P108 669E

Servo Control Orifice Reassembly
1. Install the orifice (G020), and torque to 2.7 N•m [23 in•lb]. Then install the orifice backup plug (G030),
and torque to 2.7 N•m [23 in•lb].
2. Install the PC spool (C132), spherical end first, into the PC bore. Install plug (C103). Torque the plug to
12 N•m [8.9 lbf•ft].
3. Using petroleum jelly to retain them, install the four O-rings (C200) in the recesses on the control
housing.
4. Install the control assembly onto the endcap using four screws (C300). Torque the screws to 6.5 N•m[4.8 lbf•ft]. Torque screws in a criss-cross pattern and re-torque the first screw to ensure proper torqueretention.
Plug and fitting sizes and torques
If any plugs or fittings are removed from the unit during service, install and torque as indicated here. Thisdrawing is a composite. Your configuration may differ but here is the appropriate wrench size andtorque:© Danfoss | November 2023

AX152886481532en-000306 | 41

Service Manual
Series 45 J Frame Open Circuit Axial Piston Pumps
Minor Repair
Plug locations, sizes, and torques
K040

J041
1/4 inch

3/8 inch

55 - 135 N•m[40 - 100 lbf•ft]

27 - 47 N•m[20 - 35 lbf•ft]

K040A
J041A

K070A
K070
3/8 inch

55 - 135 N•m[40 - 100 lbf•ft]

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© Danfoss | November 2023

AX152886481532en-000306