Service Manual

Open Circuit Axial Piston Pumps
Series 45 Frame K and L

www.danfoss.com

Service Manual
Series 45 Frame K and L Open Circuit Axial Piston Pumps

Revision history

2 | © Danfoss | April 2021

Table of revisions
Date

ChangedRev

April 2021

Changed document number from 'AX00000040' and '520L0532' to 'AX152886485004' andcorrected electric control drawing

0504

August 2016

Updated tables and Adjustments chapter

0401

April 2016

minor deits - Engineering Tomorrow

0301

October 2014 updates for DITA CMSBBAugust 2014

BA

Danfoss layout

AX152886485004en-000504

Service Manual
Series 45 Frame K and L Open Circuit Axial Piston Pumps
Contents
Introduction
Using this manual.............................................................................................................................................................................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
The system circuit.............................................................................................................................................................................7
Technical specifications
General specifications.....................................................................................................................................................................9Type of mounting....................................................................................................................................................................... 9
Auxiliary mounting pad options............................................................................................................................................9Control options............................................................................................................................................................................9Port options...................................................................................................................................................................................9
Direction of rotation...................................................................................................................................................................9
Installation position....................................................................................................................................................................9Technical specifications............................................................................................................................................................9
Hydraulic parameters................................................................................................................................................................... 10
Inlet pressure..............................................................................................................................................................................10
Pressure compensator valve setting..................................................................................................................................10
Case pressure............................................................................................................................................................................. 10
Hydraulic fluid ...........................................................................................................................................................................10
Temperature range (1)............................................................................................................................................................10
Fluid viscosity.............................................................................................................................................................................10
Filtration ......................................................................................................................................................................................10
Features
Displacement limiter.....................................................................................................................................................................11
Auxiliary mounting pads............................................................................................................................................................. 11
Input shafts.......................................................................................................................................................................................11
Control options...............................................................................................................................................................................11
Operation.....................................................................................................................................................................................11
Electronic Controls................................................................................................................................................................... 14
Pressure measurement
Required tools................................................................................................................................................................................. 15Port locations and gauge installation.....................................................................................................................................15
Initial start-up procedures
General...............................................................................................................................................................................................16
Start-up procedure........................................................................................................................................................................ 16
Fluid and filter maintenance
Recommendations........................................................................................................................................................................ 17
Troubleshooting
Excessive noise and/or vibration..............................................................................................................................................18
Actuator response is sluggish....................................................................................................................................................18
System operating hot...................................................................................................................................................................18
Low pump output flow................................................................................................................................................................19
Pressure or flow instability..........................................................................................................................................................19
System pressure not reaching PC setting............................................................................................................................. 20
High inlet vacuum..........................................................................................................................................................................20
Adjustments
PC control..........................................................................................................................................................................................21
LS control.......................................................................................................................................................................................... 22
Displacement limiter.....................................................................................................................................................................23
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Service Manual
Series 45 Frame K and L Open Circuit Axial Piston Pumps
Contents
Shaft seal replacement.................................................................................................................................................................25
Auxiliary pads.................................................................................................................................................................................. 25
LS and PC Controls.........................................................................................................................................................................27
Electric Controls..............................................................................................................................................................................29
Servo Control Orifice.....................................................................................................................................................................31
Plug and fitting sizes and torques........................................................................................................................................... 31

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Series 45 Frame K and L Open Circuit Axial Piston Pumps
Introduction
Using this manualThis manual includes information for the normal operation, maintenance, and service of the Series 45
frame K and L open circuit pumps. The manual includes a description of the units and their individualcomponents, troubleshooting information, adjustment instructions and minor repair procedures. Unit
warranty obligations should not be affected if maintenance, adjustment and minor repairs are performed
according to the procedures described in this manual.
Many service and adjustment activities can be performed without removing the unit from the vehicle ormachine. However, adequate access to the unit must be available, and the unit must be thoroughly
cleaned before beginning maintenance, adjustment, or repair activities. Since dirt and contamination are
the greatest enemies of any type of hydraulic equipment, follow cleanliness requirements strictly. This isespecially important when changing the system filter and when removing hoses or plumbing.
A worldwide network of Danfoss Authorized Service Centers (ASCs) is available should major repairs beneeded. Contact any Danfoss ASC for details. A list of all ASCs can be found in bulletin BLN-2-40527, or inbrochure SAW (Ident. No. 698266), or you can locate your nearest ASC using the distributor locator at
http://www.powersolutions.danfoss.com
Safety precautions
Always consider safety precautions before beginning a service procedure. Protect yourself and othersfrom injury. Take the following 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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Service Manual
Series 45 Frame K and L 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 K and L 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 Frame K and L 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, operation.
Pump and control sectional view
LS control(attached to endcap)
LS adjustment screw

LS spool

PC adjustment screw

PC spool
Swashplate

Servo piston

Bias spring

Tapered roller bearing

Valve plate
Endcap(axial ported)

Input shaft
Shaft seal

Block spring
Cylinder block

PistonSlipper
Slipper retainer

P101 659E

The 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 demands while limiting the maximum pressure. Therefore flow and pressure in thesystem are compensated to meet requirements.

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Service Manual
Series 45 Frame K and L Open Circuit Axial Piston Pumps
Introduction
Pictorial circuit diagram
K/LFrame Series 45
open circuit axial
piston pump withload sensing contro l

Double-ac ting cylinder

PVG 32
mulit-sec tionload
sensing
contro lvalve

Bi-directional
gear moto r

System pressur eReservoir

FilterHeat exchanger

Servo pressur e
Actuator pressur e
Load sense pressur e
Actuator retur n

P101 658E

Suction / case drain /system retur n

Full available flow is a function of pump displacement, operating speed, and efficiency. Refer to Series 45
Axial Piston Open Circuit Pumps Technical Information, BLN-10128 for details.

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Series 45 Frame K and L Open Circuit Axial Piston Pumps
Technical specifications
General specifications
Type of mounting
SAE-B mounting flange.
Auxiliary mounting pad options
SAE-A, SAE-B, or SAE-B-B
Control options
PC: Pressure Compensator
LS: Load Sensing (with PC)
Port options
Inlet and system ports:• SAE flanged ports, code 61 or O-ring boss ports.

•

Axial (end) ports or radial (side) ports.

All other ports:
SAE straight thread O-ring boss.

•

Direction of rotation
Clockwise or counterclockwise.
Installation position
Installation position is discretionary. To satisfy inlet pressure conditions, it is recommended that thepump always be located below the lowest level of hydraulic fluid in the reservoir. The housing must
always be filled with hydraulic fluid.
Technical specifications
Ratings
Specification

Unit

Frame L

Displacement

cm3 [ in3]

25 [1.53]

30 [183]

38 [2.32]

45 [2.75]

Input speed

min-1 (rpm)minimum

Frame K

500

500

500

500

continuous

3200

3200

2650

2650

maximum

3600

3600

2800

2800

350 [5075]

300 [4350]

350 [5075]

300 [4350]

Working pressure - maximum (peak)bar [psi]

Continuous working pressure
Flow at rated speedl/min [gal/min]

76.2 [20.3]

90.0 [24.0]

108.3 [20.9]

126.0 [33.6]

Theoretical input torque at maximum displacementN•m/bar [lbf•in/1000 psi]

0.395 [243]0.477 [291]0.605 [369]0.716 [437]

Mass moment of inertia of internal rotating componentskg•m2[lbm•ft2]

0.0016 [0.037]

0.0015 [0.035]

0.0017 [0.040]

0.0020 [0.047]

Weightkg [lbm]

19 [42]

19 [42]

19 [42]

19 [42]24 [53]24 [53]24 [53]24 [53]

Axial ports
Radial ports© Danfoss | April 2021

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Service Manual
Series 45 Frame K and L Open Circuit Axial Piston Pumps
Technical specifications
Hydraulic parameters
Inlet pressure
Minimum pressure, continuous = 0.8 bar absolute [23.2 in Hg] (at reduced maximum pump speed)
Minimum pressure, cold start = 0.5 bar absolute [14.8 in Hg]
Pressure compensator valve setting
Minimum: 100 bar [1450 psi]
Maximum: 260 bar [3770 psi]
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 (1)Intermittent (cold start): - 40° C [- 40° F]
Continuous: 82° C [180° F]
Maximum: (2) 104° C [220° F](1) Hydraulic fluid viscosity must be maintained within the prescribed limits.
(2) 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 Frame K and L Open Circuit Axial Piston Pumps
Features
Displacement limiter
Frame K and L Series 45 pumps are available with an optional maximum displacement limiter. If installed,
this longer servo piston will limit the maximum displacement to 92%. This displacement limiter is not
adjustable.
Displacement limiter

P101 660

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 Axial Piston Open Circuit Pumps Technical Information BLN-10128.
Auxiliary mounting pads

P101 661

Input shafts
Series 45 K and L frame pumps are available with a variety of splined, straight keyed, and tapered end
shafts. For information on shafts refer to Series 45 Axial Piston Open Circuit Pumps Technical Information
BLN-10128.
Control options
The Series 45 Frames K and L have two possible control options, a Load Sensing (LS) control with Pressure
Compensator (PC) or a PC only control.
Operation

GeneralThe bias spring (1) acts at all times to push the swashplate (2) to maximum angle causing the pump to
stroke. The servo piston (3) acts against the bias spring to reduce the swashplate angle causing the pump
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Service Manual
Series 45 Frame K and L Open Circuit Axial Piston Pumps
Featuresto de-stroke. Swashplate angle determines pump outlet flow. The pump control, depending on
conditions in the system circuit, sets swashplate angle by metering system pressure to the servo piston.
Cross-section pump: Bias spring and servo piston set swashplate position

PC control
The PC control is designed to maintain 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 defined by
the PC adjustment screw (4) and spring (5).
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: PC spool shifts to port system pressure to servo piston
System pressur eCase pressur e

45Servo pressur e

6
P101 662E

LS control
The LS control is designed to match pump flow with system demand. The flow demand of the system issensed by the LS control as a pressure drop across the External Control Valve (ECV). As the ECV opens andcloses, the pressure 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 thepressure delta becomes equal to the LS setting as defined by the LS adjustment screw (7) and spring (8).

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Series 45 Frame K and L Open Circuit Axial Piston Pumps
Features
Typical load-sensing control valve:Pressure drop across external control valve defines system demandLoadpressur e

Returnpressur e
Tank

Load sensepressur e

Systempressur e

P101 665E

Cross-section LS control: LS spool shifts to port system pressure to servo piston
System pressur e
LS pressure
7 8
9

4
5
Case pressur eServo pressur e

6
P101 664E

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 described in theprevious section. The LS spool (9) controls the load-sensing function. The PC spool has priority over the
LS spool.
Via internal porting, system pressure (upstream of ECV) is applied to the non-spring end of the LS spooland via hydraulic line connected at port X, LS pressure (downstream of ECV) is applied to the spring 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 de-stroke.

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Service Manual
Series 45 Frame K and L Open Circuit Axial Piston Pumps
Features
Electronic Controls

L and K 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.

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.

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Series 45 Frame K and L 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
Gauge port locations are shown below. Recommended pressure gauges and fittings are detailed in thetable.
Gauge and port information
Port

PurposeRange of gauge

Fitting

M2

System pressure

0-300 bar [0-5000 psi]

7/16 - 20 O-ring fitting

M4

Servo pressure

0-300 bar [0-5000 psi]

7/16 - 20 O-ring fitting

L1, L2

Case drain port

0-10 bar [0-100 psi]

7/8 - 14 O-ring fitting

X1

LS signal

0-300 bar [0-5000 psi]

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

Gauge port locations, axial ported units

System gauge po rt M2
SAE J1926/1,0.4375-20

LS signal port X
SAE J1926/1,0.4375-20

Outlet po rt B
SAE J1926/1,1.3125-12
Case drain po rt L2
SAE J1926/1,0.875-14

Inlet po rt S
SAE J1926/1,1.875-12

Case drain po rt L1
SAE J1926/1,0.875-14

P101 634E

Gauge port locations, radial ported units
Case drain po rt L1
SAE J1926/1,0.875-14

Inlet po rt S
Case drain po rt L2 SAE J1926/1,1.875-12
SAE J1926/1,0.875-14© Danfoss | April 2021

System gauge po rt M2
SAE J1926/1,0.4375-20

Outlet po rt B
SAE J1926/1,1.3125-12

P101 635E

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Service Manual
Series 45 Frame K and L 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 port M2 (or equivalent system pressure measurement port if M2 not present) tomonitor 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 M2 or equivalent system pressure measurement port,
jog the prime mover or run at the lowest possible speed until system pressure builds to normal levels(minimum 11 bar [160psi]). 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 to Troubleshooting on page 18.
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 Adjustments on page 21.
10. Shut down the prime mover and remove the pressure gauge. Replace plug at port M2 or equivalent.
11. Check the fluid level in the reservoir; add clean filtered fluid if necessary.
The pump is now ready for operation.

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Series 45 Frame K and L 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© Danfoss | April 2021

Reservoir type

Maximum change interval

Sealed2000 hours

Breather

500 hours

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Service Manual
Series 45 Frame K and L 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.

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 operation or use
fluid with the appropriate viscosity grade for
expected operating temperatures. See Hydraulicfluids, Series 45 Technical Information Manual ,BC152886483703.

Actuator response is sluggish

System operating hot

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Service Manual
Series 45 Frame K and L 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 PC and LS control setting.

Low PC setting will prevent the pump fromachieving full stroke. Low LS setting will limit
output flow.

Adjust PC and LS setting. Refer to Adjustments on
page 21.

Check pump inlet pressure/vacuum.

High inlet vacuum adds heat to system.

Correct inlet pressure/vacuum conditions.

Check input speed.

Low input speeds decrease flow.

Adjust input speed.

Check pump rotation.

Incorrect rotational configuration will cause low
flow.

Use pump with appropriate rotational
configuration.

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© Danfoss | April 2021

AX152886485004en-000504 | 19

Service Manual
Series 45 Frame K and L 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 Frame K and L Open Circuit Axial Piston Pumps
Adjustments

PC control
PC setting is indicated in the pump model code. Refer to the Series 45 Open Circuit Axial Piston Pumps
Technical Information Manual, BLN-10128, for more information.
Before performing adjustments, read Pressure measurement, for recommendations.
1. Install a pressure gauge in port M2 to measure system pressure. Install a pressure gauge in case drain
port L1 or L2 to measure case pressure.

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.

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 adjustment screw until the desired setting is indicated on
the pressure gauge at port M21. Clockwise rotation will increase pressure, counterclockwise rotation
will decrease; approximate gain = 35 bar [507 psi] per turn.
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 adjustment screw, torque the PC set screw to 9 N•m [7 lbf•ft].
5. Stop the prime mover, remove the pressure gauges, and return the system to its normal operating
configuration.
PC control adjustment: Adjustment screw, set screw, and gauge locations shown

M2

L1
PC adjustment screw
PC set screw

P101652

Item

Description

Gauge

Port size

Wrench size

TorqueM2

Gauge port

300 bar [5000 psi]

9/16-18

1/4 inch internal hex

51 N•m [38 lbf•ft]

M14

4 mm internal hex

31 N•m [23 lbf•ft]

1

PC setting is referenced to case pressure. Subtract case pressure from system pressure to compute the actual setting.

© Danfoss | April 2021

AX152886485004en-000504 | 21

Service Manual
Series 45 Frame K and L Open Circuit Axial Piston Pumps
Adjustments
Item

Description

Gauge

Port size

Wrench size

Torque

L1

Case drain port

10 bar [100 psi]

7/8-14

3/8 internal hex

95 N•m [70 lbf•ft]

PC adj. screw

PC adjustment screw--

6 mm internal hex-

PC set screw

PC set screw

-

-

4 mm

9 N•m [7 lbf•ft]

LS control
The LS 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.
Before performing adjustments, read Pressure measurement, for recommendations.
1. Install a pressure gauge in port M2 (or equivalent system pressure measurement port if M2 notpresent) to measure system pressure. Install a pressure gauge in drain port L1 or L2 to measure casepressure. 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
the mechanism 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 which 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 adjustment screw until thedesired pressure differential between the system port gauge (port M2 if available) and port X isachieved. Clockwise rotation will increase the setting, counterclockwise rotation will decrease;approximate gain = 12 bar [170 psi] per turn.
4. While holding the position of the LS adjustment screw, torque the LS set screw to 9 N•m [7 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 adjustment screw until the desired setting is indicated on
the pressure gauge at port M22. Clockwise rotation will increase pressure, counterclockwise rotation
will decrease; approximate gain = 35 bar [507 psi] per turn.2
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.
7. While holding the position of the PC adjustment screw, torque the PC set screw to 9 N•m [7 lbf•ft].

2

PC setting is referenced to case pressure. Subtract case pressure from system pressure to compute the actual setting.

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Service Manual
Series 45 Frame K and L 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: Adjustment screw, set screw, and gauge locations shown
M2
L1
LS adjustment
screw
B
PC adjustment
screw

Item

Description

Gauge

Port size

Wrench size

TorqueM21

Gauge port

300 bar [5000 psi]

9/16-18

1/4 inch internal hex

51 N•m [38 lbf•ft]

M14

4 mm internal hex

31 N•m [23 lbf•ft]

L1

Case drain port

10 bar [100 psi]

7/8-14

3/8 internal hex

95 N•m [70 lbf•ft]

X

LS/remote PC signal port

-

-

-

-

LS adj. screw

LS adjustment screw--

6 mm internal hex-

LS set screw

LS set screw

-

-

4 mm

9 N•m [7 lbf•ft]

PC adj. screw

PC adjustment screw--

6 mm internal hex-

PC set screw

PC set screw

-

-

4 mm

9 N•m [7 lbf•ft]

1 The M2 port is not available as a standard option.

Displacement limiter
L and K Frame open circuit pumps are available with an optional adjustable displacement limiter. Thisadjustable stop limits the pump’s maximum displacement.
Cross-Section

P104 084

Setting range© Danfoss | April 2021

L25C

0 to 25 cm³ [0 to 1.53 in³]

L30D

0 to 30 cm³ [0 to 1.83 in³]

K38C

0 to 38 cm³ [0 to 2.32 in³]

K45D

0 to 45 cm³ [0 to 2.75 in³]

AX152886485004en-000504 | 23

Service Manual
Series 45 Frame K and L Open Circuit Axial Piston Pumps
Adjustments
Displacement per turn
L25C

1.20 cm³/rev [0.07 in³/rev]

L30D

1.43 cm³/rev [0.09 in³/rev]

K38C

1.81 cm³/rev [0.11 in³/rev]

K45D

2.15 cm³/rev [0.13 in³/rev]

Installation Dimensions
222[8.74]

83.3[3.28]

P104 065E

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Service Manual
Series 45 Frame K and L Open Circuit Axial Piston Pumps
Minor repair
Shaft seal replacement
A lip type shaft seal is used in the Series 45 open circuit variable pumps. This seal can be replaced withoutmajor disassembly of the unit. Replacement of the shaft seal requires removal of the pump from themachine.
Shaft seal and retaining ring
K010
K020

P101 637

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. Avoid damaging thepump housing or shaft.

Puncture the face of the seal with a packing hook, or use a slide-hammer type puller to remove theseal.
3. 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.
4. 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.

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.
5. Keeping the seal perpindicular 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.
6. Using the appropriate snap ring pliers, install the seal retaining ring.
7. Remove the installation sleeve.
Auxiliary pads
Auxiliary mounting pads may be installed on pumps equipped with through-drive radial ported endcaps.
Follow these steps to either remove, replace, or exchange auxiliary mounting pads.

© Danfoss | April 2021

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Service Manual
Series 45 Frame K and L Open Circuit Axial Piston Pumps
Minor repair
Auxiliary mounting pads

J140

J095
J090
J085
J120
J110

J095
J100 (4pl.)
8mm

J085

J140

J090
J095

47-61 N•m
[35-45 lbf•ft]

J085

J130 (2pl.)
9/16 in
37-50 N•m
[27-37 lbf•ft]

J120
J110

J100 (4pl.)
8mm
47-61 N•m
[35-45 lbf•ft]
P101638

1. Remove two screws (J130) retaining the cover plate (J110) or auxiliary pump (not shown). Remove theshipping cover or auxiliary pump and its sealing O-ring (J120). Discard the O-ring.
2. Remove the drive coupling (J140).
3. Remove the four screws (J100) retaining the pad adapter (J085) to the endcap. Discard the two pad
adapter O-rings (J090, J095).
4. Lubricate new O-rings with petroleum jelly. Install the pad adapter to the endcap.
5. Install the four screws and torque to 47-61 N•m [35-45 lbf•ft].
6. Install the drive coupling.
7. Install shipping cover or auxiliary pump with new O-ring.

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 two screws (J130) and torque to 37-50 N•m [27-37 lbf•ft].

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Service Manual
Series 45 Frame K and L Open Circuit Axial Piston Pumps
Minor repair
LS and PC Controls
Control assembly: LS control shown; parts C106 and C112 through C118 are not used on PC control
C118
6mm
C138
6mm
C136

C117
C116
C117

C135
C114
C134
C115

C133

C113

C102 (2pl.)
4mm
7-11 N•m[6-8 lbf•ft]

C200
C107A

C300 (4pl.)
5mm

C107
3/16 in

15-18 N•m
[11-13 lbf•ft]

11-14 N•m
[8-10 lbf•ft]

C132

C112
C106A

C103A
C103
3/16 in11-14 N•m
[8-10 lbf•ft]

C106
3/16 in11-14 N•m
[8-10 lbf•ft]

P101 667

Disassembly
1. Remove the four screws (C300) holding the control housing onto the end cap.
2. Remove the control and discard the three interface O-rings (C200).
3. Remove the PC set screw (C102), PC adjustment screw (C138), O-ring (C136), springs (C135, C134),and seat (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.
5. Remove the plug (C107) and O-ring (C107A); discard the O-ring.
For PC only controls, skip steps 6 and 7.
6. Remove the LS set screw (C102), LS adjustment screw (C118), O-ring (C116), back-up rings (C117),
springs (C114, C115), and seat (C113); discard the O-ring.
7. Remove the plug (C106), O-ring (C106A), and LS spool (C112) from the control housing; discard the Oring. Note orientation of the spool for reassembly.
© Danfoss | April 2021

AX152886485004en-000504 | 27

Service Manual
Series 45 Frame K and L Open Circuit Axial Piston Pumps
Minor repair
Inspection
1. Inspect the adjustment screws 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. Clean all parts and lubricate spools, springs, guides and new O-rings with clean hydraulic fluid.
Reassembly
1. Install the PC spool, spherical end first, into the PC bore. The PC spool is the shorter of the two. Usinga new O-ring, install the plug (C103). Torque to 11-14 N•m [8-10 lbf•ft].
2. Place the two PC springs onto the spring guide and install into the PC bore. Place a new O-ring onto
the PC adjustment screw and thread it into the PC bore until flush, then make another full turn. Install
and torque the set screw to 7-11 N•m [6-8 lbf•ft].
For PC only controls, skip steps 15 and 16.
3. Install the LS spool, spherical end first, into the LS bore. The LS spool is the longer of the two. Using a
new O-ring, install the plug (C106). Torque to 11-14 N•m [8-10 lbf•ft].
4. Place the two LS springs onto the spring guide and install into the LS bore. Place a new O-ring andback-up rings onto the LS adjustment screw and thread it into the LS bore until flush, then makeanother full turn. Install and torque the set screw to 7-11 N•m [6-8 lbf•ft].
5. Using a new O-ring, install the plug (C107). Torque to 11-14 N•m [8-10 lbf•ft].
6. Using petroleum jelly to retain them, install the three interface O-rings (C200) in the recesses on thecontrol housing.
7. Install the control assembly onto the endcap using the four screws (C300). Torque to 15-18 N•m[11-13 lbf•ft]. Torque screws in a criss-cross pattern and re-torque the first screw to ensure proper
torque retention.
8. Check and adjust the control setting. See Adjustments.

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Service Manual
Series 45 Frame K and L Open Circuit Axial Piston Pumps
Minor repair
Electric Controls
Control assembly

C138
6mm

C118
6mm

C134

C140

C114

C145
C135

C115
C200 (3pl.)

C150
Cartridge
3/4 in24-27 N•m
[18-20 lbf•ft]

C133
C113
C102 (2pl.)
4mm
7-11 N•m[6-8 lbf•ft]

Coil Nut
3/4 in5-7 N•m
4-5 [lbf•ft]

C149
6mm

C155

C300
5mm
15-18 N•m
[11-13 lbf•ft]

C108
7/16 in
28-39 N•m
[21-29 lbf•ft]

C300
5mm
15-18 N•m
[11-13 lbf•ft]

C112

C132

C103
3/16 in11-14 N•m
[8-10 lbf•ft]

C107
3/16 in11-14 N•m
[8-10 lbf•ft]

C104
3/16 in11-14 N•m
[8-10 lbf•ft]
P108 670E

Disassembly
1. Remove four screws (C300).
2. Remove the control and discard the three O-rings (C200).
3. Remove set screws (C102), PC adjusting screw (C138), springs (C134, C135), and seat (C133).
4. Remove plug (C103). Remove PC spool (C132). Note orientation of the spool for reassembly.
5. Remove the plug (C107).
6. Remove the LS set screw (C102), LS adjustment screw assembly (C118), springs (C114, C115), and seat
(C113). Discard the LS adjustment screw assembly.
7. Remove plug (C104), and spool (C112). Note the orientation of the spool for reassembly.
© Danfoss | April 2021

AX152886485004en-000504 | 29

Service Manual
Series 45 Frame K and L Open Circuit Axial Piston Pumps
Minor repair
8. Remove the plug (C105).
9. Remove the solenoid coil nut, and electric solenoid coil (C155). Remove the cartridge valve (C150).
Remove filter screen plug (C145), and O-ring (C140).
10. Remove the plug (C108) and electric control manifold drain orifice (C149).
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. Ensure the electric control manifold drain orifice is clean. Remove debris from orifice if necessary.
6. Clean all parts and lubricate spools, springs, guides and new O-rings with clean hydraulic fluid.
Reassembly
1. Install the PC spool, spherical end first, into the PC bore. The PC spool is the shorter of the two. Install
plug (C103). Torque to 11-14 N•m [8-10 lbf•ft].
2. Thread the PC adjustment screw into the PC bore until flush, then make another full turn. Install andtorque the set screw (C102) to 7-11 N•m [6-8 lbf•ft].
3. Install the LS spool, spherical end first, into the LS bore. The LS spool is the longer of the two. Install
plug (C106). Torque to 11-14 N•m [8-10 lbf•ft].
4. Place the two LS springs onto the spring guide and install into the LS bore. Use a new LS adjustment
screw assembly (C118) and thread it into the LS bore until flush, then make another full turn. Install
and torque the set screw (C102) to 7-11 N•m [6-8 lbf•ft].
5. Install plug (C107). Torque to 11-14 N•m [8-10 lbf•ft].
6. Install plug (C105). Torque to 11-14 N•m [8-10 lbf•ft].
7. Install filter screen plug (C145) and O-ring (C140). Install the cartridge valve (C150) and torque to
24-27 N•m [18-20 lbf•ft]. DO NOT OVERTORQUE the cartridge valve. Install the electric solenoid coil
(C155) and solenoid coil nut; torque the nut to 5-7 N•m [4-5 lbf•ft].
8. Install the electric control manifold drain orifice (C149), torque to 2-3.4 N•m [18-30 in•lb]. Install plug
(C108). Torque the plug to 11-14 N•m [8-10 lbf•ft].
9. Using petroleum jelly to retain them, install the three interface O-rings (C200).
10. Install the control assembly onto the endcap using the four screws (C300). Torque to 15-18 N•m[11-13 lbf•ft]. Torque screws in a criss-cross pattern and re-torque the first screw to ensure proper
torque retention.
11. Check and adjust the control setting. See Adjustments.

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Service Manual
Series 45 Frame K and L Open Circuit Axial Piston Pumps
Minor repair
Servo Control Orifice
Control assembly

C132

C103
3/16 in11-14 N•m
[8-10 lbf•ft]

P108 671E

Disassembly
Remove plug (C103) and PC spool (C132) from the control housing. Keep the O-ring.
Note the orientation of the spool for reassembly.
Reassembly
1. Ensure the preferred orifice spool (C132) is selected.
2. Install the PC spool, spherical end first, into the PC bore. Install plug (C103). Torque to 11-14 N•m [8-10lbf•ft].
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 the appropriate wrench size and torque can befound here.

© Danfoss | April 2021

AX152886485004en-000504 | 31

Service Manual
Series 45 Frame K and L Open Circuit Axial Piston Pumps
Minor repair
Plug locations, sizes, and torques
J041/J043/J044/J046
M14

9/16 in

6mm

1/4 in27-35 N•m
[20-26 lbf•ft]

34-68 N•m
[25-50 lbf•ft]

K045
7/8 in3/8 in54-136 N•m[40-100 lbf•ft]

J080/J081/J082
M18

M14

8mm

6mm

41-95 N•m
[30-70 lbf•ft]

27-35 N•m
[20-26 lbf•ft]
K040
J040
(M14)
6mm
27-35 N•m
[20-26 lbf•ft]

32 | © Danfoss | April 2021

7/8 in3/8 in54-136 N•m[40-100 lbf•ft]
P101642

AX152886485004en-000504

Products we offer:

•
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•
•
•
•
•
•
•
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Cartridge valves
DCV directional control
valvesElectric converters
Electric machines

Danfoss Power Solutions is a global manufacturer and supplier of high-quality hydraulic andelectric components. We specialize in providing state-of-the-art technology and solutions
that excel in the harsh operating conditions of the mobile off-highway market as well as themarine sector. Building on our extensive applications expertise, we work closely with you toensure exceptional performance for a broad range of applications. We help you and othercustomers around the world speed up system development, reduce costs and bring vehicles
and vessels to market faster.

Gear motors

Danfoss Power Solutions – your strongest partner in mobile hydraulics and mobile
electrification.

Gear pumps

Go to www.danfoss.com for further product information.

Hydraulic integrated
circuits (HICs)
Hydrostatic motors

We offer you expert worldwide support for ensuring the best possible solutions foroutstanding performance. And with an extensive network of Global Service Partners, we also
provide you with comprehensive global service for all of our components.

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Phone: +1 515 239 6000

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Phone: +45 7488 2222

Danfoss
Power Solutions Trading(Shanghai) Co., Ltd.
Building #22, No. 1000 Jin Hai Rd
Jin Qiao, Pudong New District
Shanghai, China 201206
Phone: +86 21 2080 6201

Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to products
already on order provided that such alterations can be made without subsequent changes being necessary in specifications already agreed.
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© Danfoss | April 2021

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