Integrated automobile fluid servicing apparatus

A fluid servicing apparatus for exchanging fluids with a power steering fluid reservoir including drain and supply conduits with inline pumps coupled to a control board on a cabinet housing new and used fluid receptacles and a remote pump actuator in communication with the control board including a switch selectively operable to actuate either of said pumps to drain and fill the reservoir.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of vehicle maintenance, and more specifically, to servicing automatic transmission and power steering fluid subsystems.

Each of the numerous fluid subsystems in conventional automobiles require frequent servicing by exchanging used up or broken down fluid with fresh fluid to maintain such subsystems and thus the vehicle in top working condition and extend the life of the subsystem components and associated vehicle. In servicing these subsystems, such as the transmission fluid, engine oil, power steering fluid, engine cooling, and hydraulic fluid, it is often desirable to replace the corresponding fluids in each of these components at the same time either in accordance with a preferred maintenance plan, out of convenience, or of necessity. Two of the more common fluids requiring replacement at the same time are the automatic transmission fluid and the power steering fluid.

Initial attempts at fluid servicing devices were dedicated to exchanging fluid with a particular fluid subsystem. For instance, examples of power steering fluid exchangers may be found in U.S. Pat. No. 5,415,247 to Knorr and U.S. Pat. No. 6,035,902 to Dixon. As pointed out in the Dixon patent, an operator using of the Knorr device may damage the power steering pump due to the placement of the hose ends in the power steering fluid reservoir. Moreover, as the Dixon patent points out, it is preferable to turn the steering wheel of the vehicle during the power steering fluid exchange procedure due to delivering fresh power steering fluid into the upper portion of the fluid reservoir and withdrawing used fluid from a lower part of the fluid reservoir. However, the devices described in these patents do not appear to allow the operator such remote control facilitating the wheel turning procedure while maintaining command of the pumps. In addition both the devices in the Knorr and Dixon patents include open ended hoses to place in the power steering fluid. Thus, when the pumps are deactivated and the hoses are removed from the power steering reservoirs, the remaining fluid in the hoses often spilled adding to undesirable clean up time.

While the Knorr patent indicates that other fluid subsystems may be serviced, the use of such devices for say, servicing an automatic transmission would be unsatisfactory due to the lack of flow control features. For example, attempts to use the Knorr device to service the transmission fluid compartment would run the risk of damaging the transmission pump as well. Thus, it is unlikely that these devices would be used for other than servicing power steering fluid reservoirs and that additional fluid servicing machines would be necessary to carry out the servicing procedures of other fluid reservoirs in the vehicle.

Thus, while many of these devices have proven satisfactory in their performance for servicing a particular fluid reservoir, multiple machines are typically required to service more than one fluid subsystem thus adding time as the service technician had to couple and decouple multiple machines in order to service more than one subsystem. As multiple units were required, the service room floor required more storage space for the machines when not in use.

One such device attempting to alleviate this problem can be found in U.S. Pat. Nos. 5,806,629 and 5,853,068, both to Dixon et al. However, such device incorporates an overly complex motor pump unit and associated plumbing components adding to the overall expense of the machine.

While many of these devices have proven satisfactory in their performance there remains a push for reducing the number of components, cost of manufacture, and reduced assembly time while maintaining the capability to perform the desired procedures. What is needed is a fluid changing apparatus configured to conveniently address the needs of the fluid change operator in servicing the various fluid reservoirs in an automobile using an integrated fluid servicing apparatus having a relatively minimal component fluid transfer system, something the previous attempts have failed to achieve up to this time.

SUMMARY OF THE INVENTION

In accordance with an embodiment of the present invention, an apparatus and method for performing fluid exchange servicing functions for a vehicle is described herein and more particularly for servicing the transmission and power steering components of a vehicle system. Such servicing apparatus generally includes a used fluid receptacle coupled to a drain circuit having a drain pump and first extension for placement into a power steering fluid reservoir and a fresh fluid source coupled to an elongated supply circuit having a supply pump and a second extension for placement into said power steering fluid reservoir as well. Such pumps, receptacle, and source are carried on a portable cabinet including a control board coupled to said pumps and a remote pump actuator having at least one switch selectively operable to actuate either of said pumps from a location remote to said cabinet to drain and fill said power steering fluid reservoir.

In another aspect of the present invention, either of said drain or supply circuits includes a valve selectively operable to open and close the associated circuit.

Another feature of the present invention is the incorporation a mode selection switch including at least one mode for servicing a power steering fluid reservoir and an alternate mode for servicing an alternative fluid reservoir.

In yet another aspect of the present invention a method for exchanging fluid with said power steering fluid reservoir using a remote actuating device is provided.

Other aspects of the present invention will become apparent with further reference to the following drawings and specification.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now toFIGS. 1,3and6, an exemplary embodiment of an automotive fluid servicing apparatus, generally designated20, of the present invention is illustrated. In general, such fluid servicing apparatus is incorporated in a convenient, portable wheeled cabinet22housing a plumbing subsystem and an electrical command subsystem cooperating to drain fluid from a serviceable component, add fluid to the serviceable component, circulate fluid between the serviceable component and the apparatus, and drain collected or other stored fluid using a single, common pump24and an integrated manifold assembly26as directed by a service technician and controlled by a processor/controller28.

Plumbing Subsystem

Turning toFIGS. 3,6, and12, at the heart of the plumbing subsystem is the integrated manifold assembly26housing a fluid circuit30formed in a rectangular manifold body31having a top side33, opposing bottom side35, rear side37, front side43, and two opposing ends45,47. The body sides and ends have generally planar surfaces cooperating to form a rectangular block measuring about six inches wide by three inches deep by three inches high and defining a number of manifold ports for connecting to various conduits and other hydraulic components. In this exemplary embodiment, there are six conduit ports.

With particular reference toFIG. 12, an exhaust port32, a return port34, a drain port36, and a fresh fluid supply port38open outwardly on the rear side37of the manifold body31. While each of these ports are shown on the same side of the manifold body inFIG. 12, it will be appreciated that the ports may be placed at other suitable locations on the manifold body. For instance, these same manifold ports are shown on different sides of the manifold body31inFIG. 6for ease of description and clarity and may also provide suitable port locations and is not meant to be limiting in any manner. Other suitable locations will occur to one of ordinary skill in the art. Each manifold port is threaded for coupling with one end of a respective conduit, hose, or other suitable tubing or piping, which are in turn connected to a desired source or destination. For ease of assembly, it is preferable to thread one portion of each hose coupling into the respective threaded port opening. The threaded coupling component is constructed to allow the assembler to merely press the free end of the selected conduit into the complementary coupling component threaded into the port. Suitable couplings of this type are available from Parker Hannifin under the TrueSeal trade name.

More specifically, with reference toFIGS. 3,6, and12, a used fluid conduit39connects between the drain port36and a used fluid collection tank40to carry fluid therebetween. Similarly, the fresh fluid supply port38connects via a new fluid supply conduit41to a new fluid tank42. Such used fluid collection tank40is constructed to hold a sufficient amount of used fluid to accommodate at least complete drain procedure and preferably more. The new fluid tank42is typically constructed to hold a sufficient volume of fresh fluid to accommodate a single fill procedure and preferably has a greater capacity as well. This fresh fluid source42may be filled through a fill hole (not shown). As it is preferred that the servicing apparatus maintain a portable capability, the used and new fluid tanks are preferably mounted inside the cabinet22(FIG. 1) which is sized to accommodate the preferred tank capacities. It has been found that a 24 quart capacity for both the new and used fluid tanks accommodates most servicing procedures.

With continued reference toFIGS. 3,6, and12, further convenience is provided by a set of servicing hoses,44and46respectively for connecting between the return port34and the exhaust port32of the servicing apparatus20and the influent line and effluent line of the serviceable component such as an automatic transmission as is well known to one of ordinary skill. The use of conventional adapters is also contemplated if necessary. The connectors illustrated inFIG. 3are exemplary and not meant to be limiting in any manner as other suitable connectors will occur to one of ordinary skill. Such connection places the transmission in fluid communication with the servicing apparatus20as will be discussed below. The manifold body31further includes a suction port50and a pressure port52located on the top side53of the manifold body (FIG. 12). These ports are also threaded for receiving one part of corresponding suction and pressure hose couplings54,56, which are connected at their opposite ends to the respective suction (inlet) and pressure (outlet) sides of the pump24to place the pump in fluid communication with the manifold body31. Such suction and pressure hoses also incorporate press-in connectors for convenience of the assembler.

Still referring toFIG. 6, added to the fluid circuit30are a number of pathways formed in the manifold body31as well as a number of flow control and filtering components for routing fluid entering and exiting the manifold between the various fluid ports32,34,36,38,50and52. Referring now to FIGS.6and8–11, in this exemplary embodiment, there are four such pathways including a drain path, generally designated57, for flow of fluid as indicated by directional arrow58(FIGS. 6 and 10), a recirculation path, generally designated80, for flow of fluid as indicated by directional arrow59(FIGS. 6 and 8), a supply path, generally designated93, for fluid flow as indicated by directional arrow61(FIGS. 6 and 11), and a dump path, generally designated95, for fluid flow as indicated by directional arrow63(FIGS. 6 and 9).

It will be appreciated that the manifold body31forms a three dimensional fluid circuit and that FIGS.6and8–11are represented in a two-dimensional layout for ease of description and are not meant to be limiting in any manner. For instance, the fluid ports inFIG. 12are shown on one side of the manifold body while the same ports are shown on multiple sides of the manifold body inFIG. 6. In addition, inFIG. 6, the manifold body31is not depicted as a rectangular block as inFIG. 12. These illustrations are merely to facilitate description of the preferred embodiment. Other suitable port locations and pathways may occur to one of ordinary skill and still fall within the scope of the present invention.

With continued reference to FIGS.6and8–12, each pathway57,80,93, and95is generally tubular in transverse cross section and made up of adjacent passage segments bored into the manifold body31which are configured with straight runs meeting at right angles and compacted to minimize the size of the manifold body and further reduce hose length requirements between components coupled to the manifold body and overall hose length requirements of the servicing apparatus. Some of these right angle segments project into or out of the plane of the paper and may not be shown inFIGS. 6, or8–11. It will also be appreciated, when considered from end to end, portions of each pathway may extend outside the manifold body and include couplings or connectors of flexible or rigid material connected to one or more manifold ports.

With particular reference toFIGS. 6,10, and12, during a drain procedure as will be discussed below, fluid is normally directed in the direction of arrow58through the drain path57from the return port34to the used fluid drain port36which may be connected to the used fluid collection tank40via conduit39. Such passage57is formed by an entry bore extending into the manifold body31, viewed into the paper inFIG. 6, from the return port34to enter a short pre-filter segment64which turns downwardly at a right angle from the entry bore, toward an aperture (not shown) in the bottom side35of the body aligned with a fluid entrance into an in-line filter60to direct fluid into the filter. The filter60is coupled to a hollow, threaded nipple67projecting from the bottom side35of the manifold. The nipple is screwed into an opening in the bottom side of the manifold body and further extends outside the body providing a connective threaded stub for the filter60. After exiting the manifold through the bottom aperture to enter the in-line filter60, the drain path57then reenters the manifold body through the hollow nipple and projects upwardly into the body into a pre-drain valve segment69. About the midpoint of the body31, the pre-drain valve segment terminates at an inlet of a two-position drain/bypass solenoid valve70which may be screwed into a threaded valve port65on the top side33of the manifold body31to position the dual outlet valve70in line with both the drain path58and recirculation path80of the fluid circuit30. Such valve70includes a drain position, indicated by directional arrow66, which directs fluid entering the inlet of the solenoid70out of a drain outlet of the solenoid70and through the remainder of the drain path58(FIGS. 6,10) and a normally open bypass position, indicated by directional arrow68, which directs fluid entering the inlet of the valve70out of an alternate outlet and through a recirculation path80(FIGS. 6,8).

The valves described herein are preferably two-position, three-way magnetic solenoid valves, either size 8 or 10, which may be energized to enter into a number of alternative positions. Such valves are available from Hydac Technology Corporation in Bethlehem, Pa. Other suitable valving arrangements for directing fluid flow to or from multiple channels may also be used.

With continued reference toFIG. 10, the drain path57turns at a right angle from the longitudinal centerline of the solenoid70into a post-solenoid segment72forming the stem of a T-shaped intersection74. Then the path is bifurcated to, in one branch, enter into a used fluid connection branch75of the T-shaped intersection leading to the drain port36which may be connected to the used fluid collection tank40. Fluid entering the return port34from the serviceable component is thus normally directed along this drain path57if the drain/bypass solenoid70is energized to the drain position66for collection in the used fluid tank40.

Referring now toFIGS. 6 and 8, when the drain/bypass valve70is energized to the bypass position as indicated by directional arrow68, the recirculation path80is opened and the drain path57is blocked. The recirculation path80shares the same plumbing with the drain path57up to the drain/bypass solenoid70including the return port34, pre-filter segment64, filter60, and pre-valve segment69. Continuing through the drain/bypass solenoid valve70, when energized to the bypass position68, the recirculation passage80projects at a right angle to the longitudinal centerline of the solenoid to form an L-shaped recirculation loop leading to the exhaust port32which may be connected to the transmission inlet. Fluid entering the recirculation path from the return port34is directed through the solenoid70set in the bypass position68to exhaust port32. Such recirculation path normally serves to circulate fluid in the direction indicated by arrow59between the serviceable component and the servicing apparatus and through the filter60while bypassing the pump24, used fluid tank40, and new fluid tank42.

With continued reference toFIG. 6, and with particular reference toFIG. 11, the fresh fluid supply passage93is formed by an entry bore extending into the manifold body31from the new fluid supply port38to then turn at a right angle forming an L-shaped pre-supply valve segment82. The segments discussed herein are preferably bored into the manifold body during manufacture. Such segment terminates at a two-position dump/supply solenoid valve84which is also screwed into a threaded port85on the top side33of the manifold body31to position the valve84in line with the new fluid supply passage93(FIG. 11) and the dump passage95(FIG. 9) in the fluid circuit30. Such valve84includes a normally open supply position, indicated by directional arrow81, which receives fluid withdrawn from the new fluid supply tank42and directs it through the remainder of the supply path93(FIG. 11). The supply/dump valve84also includes a dump position, indicated by directional arrow83, which receives fluid being dumped from the used fluid tank40and directs such fluid on through the remaining portion of the new fluid supply passage as well (FIG. 9).

Continuing with the new fluid passage93, a pre-suction port segment86projects at a right angle to the longitudinal centerline of the solenoid84and further includes a second right angle turn leading to the suction port50(FIGS. 6 and 11). The suction side hose54connects the suction port to the suction side of the pump24and a pressure side hose56connects the pressure side of the pump24with the pressure port52at the top side33of the manifold body31to position the pump24in line with the supply path93(FIG. 11) and also the dump path95(FIG. 9) depending on the valve84position. Reentering the manifold body31through the pressure port, the new fluid supply passage93projects downwardly through a pre-supply filter segment87to lead to an aperture (not shown) on the bottom side of the manifold body31aligned with an entry hole in a supply filter88. The supply filter88is also connected to the manifold body via a hollow, threaded nipple90on the under side35(FIG. 12) similar to the drain filter60connection. Exiting the filter88through the hollow nipple90, the new fluid supply path93projects upwardly into the manifold body31through an in-line one-way check valve92and then turns outwardly toward the back side37of the manifold body in an L-shaped segment94leading to the exhaust port32which may be connected to the transmission inlet or collection tank via servicing hose46. The final segment94of the new fluid supply path93leading to the exhaust port32is common with the last segment of the recirculation path80.

The check valve92is incorporated in the supply fluid circuit93to prevent fluid from backflowing or otherwise entering the outlet of the supply filter88from the recirculation path. This feature also serves to keep the pump24primed in use. However, it is preferable to select a suitable pump24having an integrated check valve for incorporation into the servicing apparatus20so that the external check valve92can be omitted altogether. The supply pathway93normally serves to conduct fluid in the direction of arrow61from the fresh fluid supply42connected to the new fluid port38and direct the fluid to the exhaust port32and to the upstream line of the serviceable component via servicing hose46to supply fresh fluid thereto. Alternatively, such passage93can be used to drain the new fluid tank42when the servicing hose46is coupled to a collection tank.

Turning now toFIGS. 6 and 9, the fluid circuit30also includes the used fluid dump pathway95for transporting fluid in the direction of arrow63between the drain port36and the exhaust port32for draining fluid from the used fluid tank40using the common pump24. With continued reference toFIG. 9, the dump path95begins with at the drain port36which is normally coupled to the used fluid collection tank40via the used fluid conduit39. The dump path95is then formed with a bore projecting inwardly from the drain port36along a straight segment to form the first branch75of the T-intersection74. The path95bifurcates at intersection74to flow through to a straight pre-valve segment91to one inlet of the dual inlet dump/supply solenoid valve84which controls the flow on to the outlet bore86(pre-suction port segment) leading to the suction port50when the valve is energized to the dump position83. The remaining portion of the dump path is common to the new fluid supply path93as it exits the solenoid84ultimately leading to the exhaust port32including passage through the outlet bore86through the suction port50to the inlet of the pump24via coupling54. The fluid is then directed through the outlet of the pump24through coupling56to pressure port52on through filter88, check valve92to exhaust port32. Such path95normally serves to direct fluid withdrawn from the used fluid collection tank40in the direction of arrow63using the common pump24to direct used fluid through the exhaust port32. Instead of connecting the service hose46to the transmission, however, the free end of the service hose is typically placed in a waste fluid receptacle (not shown) for future storage so that the used fluid tank40may be drained.

With continued reference to FIGS.6and8–11, fluid typically enters the return port34from conduit44connected to the downstream port of the transmission and exits the exhaust port32to be directed through hose46to the upstream port of the transmission. Fluid is generally circulated through the fluid circuit30by the single, non-reversible pump24interposed in the supply and dump pathways93and95, respectively, to complete these pathways. Fluid may also be circulated by a pump associated with the serviceable component through the drain and recirculation paths57and80, respectively. Direction of the fluid through the fluid circuit30is normally determined by the respective positions of the single inlet, dual outlet, drain/bypass valve70and dual inlet, single outlet, dump/supply valve84. The drain/bypass valve70operates to direct fluid entering the return port34through the drain or bypass passages57and80respectively with one side of the valve70in fluid communication with the return port34and the second side in fluid communication with the drain port36and exhaust port34. When solenoid70enters into the drain position66, the bypass passage80is blocked off and the passage between the return port34and the drain port36is open and fluid may flow in the direction of arrow58(FIG. 10). On the other hand, when the valve70is energized to the bypass position68, the drain passage57is blocked off and the passage between the return port34and the exhaust port32is open establishing a bypass loop80wherein fluid may circulate in the direction of the arrow59and wherein fluid does not circulate through the pump24(FIG. 8).

Referring toFIGS. 6,9, and11, connected in fluid communication with the supply and dump paths93and95, respectively, is the dump/supply valve84with the outlet of the valve in fluid communication with the exhaust port32and the dual inlet in fluid communication with the drain port36and new fluid supply port38. When the valve84is energized to the supply position81, the dump passage95is blocked off and the passage93between the new fluid supply port38and the exhaust port32is open so that fluid may flow in the direction of arrow61(FIG.11). On the other hand, when the valve84is energized to the dump position83, the new fluid supply passage93is blocked off and the passage between the drain port36and the exhaust port32is open establishing a passage95for dumping fluid in a direction indicated by arrow63to be collected in the used fluid tank40by withdrawing such fluid with the common pump24(FIG. 9). Selection of these valve positions66,68,81, and83is directed by the controller28and the operator or service technician using the electrical command system as will now be described.

Electrical Command Subsystem

Referring now toFIGS. 1–3, and6, the heart of the electrical command sub-system is the controller28which is a programmable circuit board having a central processing unit (CPU) and associated memory for transmitting control commands to the pump24or valves70,84in accordance with command sequences stored in the memory responsive to feedback transmitted from a number of sensors to direct the fluid service operations selected by a service technician. In this exemplary embodiment, there are three such sensors.

With particular reference toFIG. 6, the controller28is connected to a new fluid tank sensor100and a used fluid tank sensor102through their respective electrical leads104and106to provide fluid level feedback for each tank,42and40, respectively. The fluid level sensors detect the fluid level in their respective fluid tanks and provide this information to the controller which includes tank geometric data and fluid density data in its memory for calculating the volume of fluid in each tank. Such fluid level sensors are preferably gas sensors, available from Motorola and constructed to monitor the air pressure in each tank. A two-port balancer system is used so that the sensors can detect outside air pressure and take into account elevation of the servicing apparatus to provide more accurate fluid level readings thereby compensating for discrepancies between sea level readings and readings taken at other altitudes.

The controller28is also in electrical communication with a pressure sensor108through electrical lead110. Such pressure sensor108is threaded into an aperture109on the top surface of the manifold body31and is used for sensing fluid pressure in the last segment94of the fluid circuit leading to the exhaust port32and providing feedback to the controller28and is primarily used to detect incorrect service hose connections during the drain procedure as will be discussed below.

With continued reference toFIG. 6, the pump24, drain/bypass valve70, and dump/supply valve84are in electrical communication with the controller28via their respective electrical connectors112,114, and116. Using feedback from the sensors and any additional operator input, the controller energizes the first and second valves70and84to the desired positions as will be described below and further actuates the pump24to on and off states during selected servicing procedures to circulate the fluid through the fluid circuit30from the desired source to the selected destination. Conveniently, the controller28, a control panel130, valves70and84, pump24, and sensors100,102, and108are in electrical communication with a set of battery cables120(FIG. 1). Thus, power may be supplied to such components capable of being powered by a 12 volt DC source by attaching a set of battery cables120to the vehicle's battery. It will be appreciated that such electrically powered components could also be hardwired to an alternative power source located on the servicing apparatus itself20or constructed to plug into a wall outlet.

Referring now toFIGS. 1 and 2, in this exemplary embodiment, an operator may interface with the controller28via a control panel130located on a top forward inclined surface of the cabinet22. Such control panel is generally divided into four regions including an options menu listing132presenting the available operational options, a display region134with a plurality of LEDs and a counter display136for indicating machine and operational status and displaying quantity or diagnostic information, an interactive control region138and a power steering exchange (PSX) pendant dock region140for attaching a remote control for controlling power steering fluid exchange operations which will be described in detail below.

With continued reference toFIG. 2, the options menu listing132positioned to the left side of the control panel130includes a listing of procedural options1–9, respectfully indicated as OP1–OP9as imprinted or otherwise provided on the face of the control panel (FIG. 2). The exemplary options are as follows:

OP7Auto prime the system;

OP8New fluid sensor check; and

Such exemplary options, as illustrated inFIG. 2, are accessible via an options menu button142in the control region138and engageable by a start exchange/options button144as will be described below. The display region134provides visual feedback to the operator as to the status of the fluid exchange procedures and servicing apparatus20operation. The primary indicator is the counter display136which provides a visual display of requested information such as the servicing option being invoked, fluid capacities, or other information in the form of alphanumeric messages.

Continuing withFIG. 2, further comprising the display region134are a number of LED indicators divided into four columns. The first column includes a quarts LED indicator146and a liters LED indicator148. Such indicators indicate the system of measurement being used. Next to the first column is a column of amount indicators including a 20 quart indicator150, a 16 quart indicator152, a 12 quart indicator154, and a 4 quart indicator156. Each of these indicators provides a display to the operator as to the amount of fluid selected by the operator for an exchange. For purposes of an automatic transmission fluid exchange, eight cylinder, full size vehicles or truck typically require a twenty quart exchange. Mid-size vehicles with 6-cylinders typically require a sixteen quart fluid exchange and compact, four cylinder vehicles typically require a twelve quart exchange. Sub-compact vehicles typically only require a four quart exchange.

Still referring toFIG. 2, the third column in the display region134indicates machine operation status and includes a stopped indicator158, a halted indicator160, a running indicator162, a complete indicator164, a switch hoses indicator166, and a shift to neutral indicator168. A machine status column is the fourth column in the display region134. Such machine status column includes a new ATF low indicator170, a used ATF full indicator172, an add/remove ATF indicator174, and a new/used ATF drain indicator176. The meaning of these indicators will be discussed below when the operation of the servicing apparatus is described.

Spaced below the display region134in the control region138is a first and second set of depressable buttons for initiating a variety of functions to operate the servicing apparatus10(FIG. 2). The leftmost button of the first set is a quantity button178for selecting the quantity of fluid to be transferred from one location to another. Depressing this button cycles through the quantity indicators150,152,154, and156. Next to the quantity button is positioned the exchange/options button144for initiating a fluid exchange or initiating the option selected by the options menu button142. A power steering button180for initiating a power steering fluid exchange is next in line followed by the option menu button142. The options menu button cycles through the options listed in the options menu132when depressed.

The leftmost button in the right hand set of buttons is an add ATF button182for adding automatic transmission fluid where directed by the fluid circuit30. Next to the add ATF button is a remove ATF button184. Selection of this button may be used to remove or drain ATF from the selected source. The third button is a cycle sensors button186for cycling the valves70,84between their respective positions to clear the valves prior to operation of the servicing apparatus20to ensure the valves are in proper working order. The last button is a stop button188for shutting the apparatus down completely in an emergency or other desired stop condition. Such button is preferably a larger size or otherwise stands out from the other buttons so it may be rapidly located by the operator. An illustrative servicing procedure using the above-described plumbing and electrical subsystems incorporated into a servicing apparatus20will now be described.

Operation of the Fluid Servicing Apparatus

In the field, the manifold assembly26is typically secured within an internal compartment of the servicing apparatus20using a suitable threaded fasteners screwed into a pair of mounting bores194on the front side43of the manifold body31(FIGS. 1 and 12) and comes preassembled. Such internal compartment is accessible via a removable servicing panel190. The pump24is also preferably secured inside the servicing apparatus. The control panel130is also removable and may provide an alternative access into the compartment. Near the bottom of the servicing apparatus, the used and new fluid tanks40and42, respectively are placed on a convenient shelf.

While the servicing apparatus20is typically assembled prior to operation of the servicing apparatus20, it will be appreciated that the integrated manifold assembly26has been designed to reduce assembly time and facilitate servicing in the field and that some connection may be required prior to initiating servicing procedures or during maintenance.

Referring now toFIGS. 3,6, and12, starting with the basic manifold body31with preformed fluid circuit30and built-in couplings threaded into the ports32,34,36,38,50and52, the operator may connect the used fluid conduit39by pressing one end into the drain port36and the other end is inserted into or otherwise coupled to the used fluid tank40. The supply conduit41is likewise coupled between the supply port38and the new fluid tank42. The pump24may then be connected to the top side33of the manifold body by pressing in one end of the suction hose54into the suction port50and its opposite end into the suction side inlet of the pump24. Similarly, one end of the pressure side hose56is pressed into the pressure port52its other end into the pressure side outlet of the pump24.

With continued reference toFIG. 12, the connector nipples of the valves, pressure sensor, and filter components may then be screwed into their respective threaded ports on the manifold body31. More specifically, the drain/bypass valve70is threaded into the port65to place the valve inline with the drain and bypass fluid paths,57and80respectively. The inlet of the valve70is aligned with the terminal end of the pre-filter bore34. The first outlet of the valve70corresponding to position66is aligned with the inlet to bore72and the second outlet of the drain/bypass valve70corresponding to position68is aligned with the inlet to the recirculation loop80. Likewise, the dump/supply valve84is screwed into threaded port85on the upper side33of the manifold body to place such valve in fluid communication with the supply and dump paths,93and95respectively. The first inlet of valve84corresponding to position81is aligned with the exit of pre-valve bore82and the second inlet of valve84corresponding to position83is aligned with the exit to bore91. The outlet of valve84is aligned with the entrance to post-valve bore86. The nipple of the pressure switch108is also threaded into its respective threaded aperture109on the top side33. On the bottom side35of the manifold body31, the filters60and88are screwed onto their respective nipples67and90until their respective gaskets are flush with the undersurface of the manifold providing a suitable seal. The entry port of the drain filter60aligns with the aperture occurring at the end of the pre-drain bore34. The entry port of the supply filter88aligns with the aperture occurring at the end pre-supply filter bore87. The filters are preferably of the ten micron absolute variety and the threaded nipples are preferably constructed using metric threads to inhibit a service technician from bypassing the filters. Such filters also act as maintenance indicators as fluid servicing procedures will take longer as the filters become more and more clogged obstructing fluid flow.

Each of the electrical leads of the pump24, valves,70,84, and sensor108along with the other DC powered components may then be placed in electrical communication with the controller28and battery cables120via the wiring harness.

When the service technician is prepared to service an automobile transmission, with reference toFIGS. 1–3, and6, the new fluid tank42and used fluid tank40may initially be empty. The servicing apparatus20is initially prepped for servicing by filling a quantity of new transmission fluid through a fill hole (not shown) into the new fluid tank42. For purposes of this operational procedure, it will be assumed that the used fluid tank40is initially empty and the new tank42has an adequate supply of transmission fluid to perform a complete exchange. The servicing apparatus20is wheeled over near the transmission to be serviced. Using well known procedures, the service technician interrupts the transmission cooling lines to expose an influent line or inlet port and an effluent line or outlet port and connects the free ends to the return and exhaust ports34and32of the manifold assembly26using the service hoses44and46using conventional adapters if necessary. Preferably, the technician connects the effluent line of the transmission to the return port34and further connects the influent line at one end to the exhaust port32such that the connection places the transmission in fluid communication with the fluid passages57,80,93, and95of the servicing apparatus20(FIGS. 1,6, and8–11). It will be appreciated that the service hoses44,46are preferably clear allowing an operator to visually check the condition of the fluid in each hose. The default position of the drain/bypass valve70is the bypass position68blocking off the drain path57so that fluid flow from the transmission will circulate through fluid passage80in the direction of arrow59initially when the vehicle engine is turned on to activate the transmission pump (FIG. 8).

With continued reference toFIGS. 6 and 8, once the service hoses44,46are connected, the technician may then connect battery cables120to the vehicle battery to supply power to the control panel130, controller28, drain/bypass valve70, dump/supply valve84, pump24, sensors100,102,108, all of which are preferably selected to run on a 12-volt DC power supply. Using the versatile servicing apparatus20, the technician may perform several servicing procedures including circulation and clean, automatic transmission fluid exchange by draining and refilling the transmission in incremental steps, draining and refilling the transmission pan, topping off fluid levels, and draining the new and used fluid tanks. It will be appreciated that the following procedures are performed using only a single common pump24operating in conjunction with the vehicle transmission pump for some procedures.

In the initial stage after the service hoses44and46are connected to the return and exhaust ports34and32and transmission cooling lines, the operator may press the cycle sensors button186to actuate the valves70and84through their full range of movement to clear any obstacles, debris, or other contaminants that may prevent performance.

With battery cables120connected, the operator may start the vehicle engine to operate the transmission pump and to pressurize fluid out of the transmission to begin circulating fluid through circulation passage80. This is commonly referred to as circulation mode during which the pressure switch108in normally inactive. Depending on the transmission pump and direction of fluid flow, used fluid from the transmission is forced out into the recirculation passage80from either the return port34or the exhaust port32. Fluid will either flow in the direction of arrow59or in a reverse direction. The fluid exits the recirculation passage80from the opposite port wherein fluid is entering and reenters the transmission through the associated servicing hose. The check valve92prevents the used fluid from entering the servicing apparatus pump24. At this point a closed circulation loop between the vehicle transmission cooling lines and servicing apparatus20is established and the running indicator162lights up on the control panel130. It will be appreciated that the used transmission fluid is directed through the filter60to remove particulate from the used fluid during this initial procedure.

While the fluid is circulating, the operator may then select the quantity of fluid to be changed via the control board130connected to the processor/controller28by depressing the quantity button178until the indicator150,152,154, or156beside the desired quantity illuminates (FIG. 2). Assuming for example, a full-sized 8-cylinder vehicle is being serviced, the operator selects the 20 quart quantity by toggling the quantity button until the desired indicator lights up. In this instance, the 20 quart indicator150will light up on the control panel. At this point, the pump24is not running and fluid is only being circulated by the transmission pump.

Turning now toFIGS. 2,6,8, and10, having selected the quantity to be exchanged, the operator presses the start exchange/options button144on the control panel130of the servicing apparatus20, which causes several actions to occur. Initially, the controller28energizes the drain/bypass solenoid70to move from the bypass position68to the drain position66to block off the recirculation passage80and open the drain path57. If the service hoses have been connected properly, used fluid entering the return port34under pressure from the transmission pump is directed through the drain path57, along the direction of arrow58, through the drain port36and used fluid conduit39connected thereto to be collected in the used fluid collection tank40. Once the valve70is energized to the drain position66, the controller28will take a reading of the used fluid tank sensor102to sense the hydrostatic pressure head therein (FIG. 6). If no fluid is sensed in the used fluid tank40, the controller will also take a reading of the signal transmitted from the pressure sensor108to determine if any fluid is entering the exhaust port32and is present in segment94. With the signal stored showing no fluid in the used fluid tank, detection of fluid entering through the exhaust port32into the recirculation passage80is indicative of an improper hose connection. If that's the case, the processor28acts accordingly to alert the operator of an improper hose coupling condition by transmitting a signal to illuminate the switch hoses indicator166on the control board130. It will be appreciated that an audible alarm may be programmed into the controller28to accompany this display or any of the displays to further alert the operator. The operator may then turn the vehicle engine off and manually switch the service hoses44and46between the respective ports32and34. Once the hoses are switched the operator restores the servicing apparatus20to circulation mode as described above.

On the other hand, if a no pressure signal is transmitted by the pressure switch108to the processor after the drain process is initiated and no fluid is detected by the sensor102in the used fluid tank40, the shift to neutral indicator168is illuminated. This occurrence may be due to the fact that, for instance, many Chrysler transmissions pump fluid only when in neutral. If the switch hoses indicator166and the shift to neutral indicator168have not lit, then the hoses are connected properly and proper fluid flow has been established. The transmission may then be serviced.

Assuming these error conditions do not occur, when the start button144is pressed the transmission pump will force the fluid from the return port34through the filter60into the drain passage57and through the solenoid valve70set in the drain position66(FIGS. 6 and 10). Used fluid passing through the solenoid70is directed to the drain port36in the direction of arrow58and expelled into the used fluid tank40. The level sensor102in the used fluid tank transmits a signal proportional to the level of the fluid entering into the used fluid tank to the processor28by sensing the hydrostatic pressure head of the fluid entering the used fluid tank. The pressure head data is used to calculate the volume of fluid in the used fluid tank as the known parameters of the tank geometry and fluid density stored in the processor are recalled by a volume calculation routine. In this exemplary embodiment, once 6/10 of a quart is collected in the used fluid tank40as calculated by the processor28, the processor will energize the drain/bypass solenoid70to reenter the bypass position68blocking off the drain passage57and forcing the fluid into the recirculation passage80in the direction of the arrow59. Other predetermined quantities could also be used. The processor28then initiates an incremental fill mode.

Turning now toFIGS. 2,6, and11, to perform the incremental fill portion of the process, the processor28will actuate the dump/supply solenoid84to cause it to assume the supply position81to open the new fluid supply path93from the new fluid tank42through the servicing apparatus pump24to the exhaust port32to the transmission via servicing hose46. The processor also actuates the pump24at this time withdrawing fluid from the new fluid tank42in the direction of arrow61and through the suction port50and suction hose54to the pump. Fresh fluid is then pumped out of the pump through the pressure hose56to pressure port52. Such fresh fluid is directed under pressure through the supply filter88and one-way check valve92and, because it can not enter the drain/bypass solenoid70due to incoming fluid pressure, is directed through the exhaust port32to the vehicle's transmission via service hose46. When the level in the new fluid tank is lowered an amount corresponding with 6/10 of a quart, the level sensor100will transmit a signal to the processor28which is programmed to respond to shut off the internal pump24and then shift the drain/bypass solenoid70back into the drain position66to repeat the incremental drain procedure.

This drain then fill process continues in an alternating, iterative manner as the processor28periodically responds to discrete drops in the level of fluid sensed by the fluid sensor100in the new fluid tank. When the quantity of the new fluid transferred out of the new fluid tank equals the preselected quantity initially set by the operator, and indicated by one of the quantity indicators150,152,154, or156, the processor will energize an exchange complete indicator164on the control board130and actuate an audible signal (FIG. 2). The processor28then shifts the drain/bypass solenoid70to the bypass position68to switch the servicing apparatus20to the recirculation mode and circulates fluid through the recirculation passage80. As before, during recirculation mode, the internal pump24is deactivated.

In this exemplary procedure, the processor is operative to, in discrete 6/10 quart increments, transfer a total of 20 quarts of fluid to the used fluid tank40and an equal volume of new fluid is withdrawn from the new fluid tank42. Responsive to the exchange complete indicator, the operator will turn the engine off and disconnect the service hoses44,46from the servicing apparatus20. The operator will then reconnect the vehicle transmission cooling loop to complete the servicing procedure. It will be appreciated that upon the operator depressing the start button144, the entire fluid exchange procedure will be performed automatically without further operator intervention until he or she turns the engine off and reconnects the transmission cooling lines, assuming no error in connection was detected. In addition, to prevent an overpressure condition during fluid exchange or other servicing procedures, a pressure relief valve (not shown) may be placed in communication with the fluid circuit30and set to relieve in response to a preselected pressure to route overpressurized fluid through a bypass. It will be appreciated that the alternating drain and fill exchange process takes place rapidly and an entire exchange for an eight cylinder vehicle can take place in approximately 10–15 minutes.

Such fluid exchange will typically leave the new fluid tank42empty or partially empty and the used fluid tank40partially full or completely full depending on the tank capacity. Should the operator then attempt to start another servicing procedure and select an exchange quantity that exceeds the amount of fluid remaining in the new fluid tank40, the processor28, having taken a reading of the new fluid sensor100, will transmit a signal to the control board130to illuminate the new ATF low indicator170to alert the operator that there is insufficient fluid in the new fluid tank42to perform the selected procedure (FIGS. 2 and 6). To refill the new fluid tank42, the operator may supply new fluid through its fill hole. During this procedure, the processor functions to illuminate the Add/Remove ATF indicator174alerting the operator that fluid is being added to the new fluid tank42.

On the other hand, should the operator select an exchange quantity that would overflow the capacity of the used fluid tank40, the processor, having taken a reading of the used fluid sensor102, will transmit a signal to the control board130to illuminate the used AFT full indicator172alerting the operator to drain the used fluid tank before proceeding. Conveniently, the fluid circuit30and common pump24enable such draining or dumping of the used fluid tank40without the assistance of a dedicated drain pump.

Referring now toFIGS. 1,2, and9, to initiate the used fluid dump procedure, the operator will connect one end of the servicing conduit46to the exhaust port32and place the free end of the servicing conduit into a fluid waste tank (not shown). The operator will then depress the options button142on the control panel130to scroll through the options menu (OP1–OP9) until the desired option is displayed in the counter display136. In this scenario, the OP4option code would be displayed in the counter display136indicating that the operator has elected to drain the used fluid tank. Conveniently, the operator may refer to the option menu132imprinted on the left side of control panel130to determine the procedure associated with the option code. Next, the operator may engage the start button144to begin the used fluid dumping procedure. In response to the operator's command, the controller28energizes the dump/supply valve84to its dump position83to open the dump passage95and then actuates the pump24to begin drawing fluid from the used fluid tank40through the open dump passage in the direction of arrow63. The fluid is expelled through the exhaust port32through the servicing conduit46and into the storage receptacle. Once the controller28detects the used fluid tank is at a predetermined bottom operating level via the used fluid level sensor102, the controller will shut the pump24off and terminate the procedure. By pressing the start button144for five seconds the operator can effect draining of the used fluid collection tank40until the stop button188is pressed. An audible alarm sounds when the used fluid tank level is empty as sensed by the used fluid sensor102and illumination of the complete indicator164on the control panel130alerts the operator that the dump procedure is completed. It will be appreciated that the plumbing circuit of the exemplary embodiment enables draining of the used fluid tank without the necessity of inverting the tank upside down to drain from its top end or incorporating an extra dedicated drain pump to draw the used fluid from the used fluid tank and direct it to a waste fluid collection receptacle.

In a similar manner, the new fluid tank42may also be drained completely as desired. Referring now toFIGS. 1,2,6, and11, as described for the used fluid tank40dumping procedure, one end of the servicing conduit46may be connected to the exhaust port32and its free end placed into a new fluid storage receptacle (not shown). In this scenario, the operator may toggle the options button142until OP3is displayed in the display counter136. Activation of the exchange/options button144will cause, the controller28to shift the dump/supply valve84to its supply position81. The pump24is also actuated and fluid is drawn from the new fluid tank42along the supply passage93in the direction of arrow61to be expelled through the exhaust port32. The expelled fluid is transferred through the servicing hose46to the new fluid receptacle for storage. The processor28is responsive to the sensor100sensing that the fluid level in the new fluid tank has fallen to a predetermined bottom operating level to shut the pump24off and terminate the drain new fluid procedure. The operator may then press and hold the start button144for five seconds to initiate a full drain of the new fluid tank42until the stop button188is pressed. An audible alarm sounds when the new fluid tank level is empty as sensed by the new fluid sensor100and the complete indicator164is illuminated by the processor on the control board130(FIG. 2).

Turning now toFIGS. 2 and 6, it will be appreciated that the operator may check the new fluid volume and used fluid capacity as calculated by the controller28. To display the new fluid volume in the new fluid tank42, the operator may depress the options button142and scroll through the options menu until OP5is displayed in the counter display136. The operator may then simply depress the start exchange/options button144and the new fluid level sensor100sends a signal to the controller28which processes the signal and displays the new fluid level in the counter display136in the measurement selected (quarts or liters). Likewise, to check the remaining capacity in the used fluid tank40, the operator may select OP6using the options menu button142and then depress the start button144. The used fluid level sensor102will detect the used fluid level in the used fluid tank40and transmit the corresponding signal to the controller28. The signal is processed and the remaining capacity is calculated and displayed on the counter display136. These features may be used by the operator prior to initiating a servicing sequence or in response to an indicator light from the control panel concerning fluid levels or any other time as selected by the operator.

With continued reference toFIGS. 1 and 6, prior to beginning a servicing sequence, the operator may desire to auto prime the servicing apparatus20. This feature is used to purge air out of the system. Preferably, at least six quarts of new fluid must be present in the new fluid tank42to initiate this procedure. After ensuring the proper fluid level in the new fluid tank, the operator connects one end of each servicing hose44and46to the respective return and exhaust ports34,32and connects the free ends of the hoses together with a priming hose (not shown) to complete the circulation loop. The operator then selects OP7by toggling the options menu button142and then depresses the start button144. During the auto prime procedure, the controller28will actuate the pump24to begin drawing fluid from the new fluid tank42through the supply path93and expelling fluid through the exhaust port32. The expelled fluid is transferred through the servicing hoses46and44and interconnecting priming hose (not shown) to the return port34. During this fluid transfer the controller28cycles the drain/bypass valve70between first and second positions66and68, respectively to build up bursts of pressure to purge unwanted air in the servicing apparatus20. Once three quarts of fluid have been transferred to the used fluid tank40, the procedure is terminated by the controller28. Such procedure is typically initiated prior to a fluid exchange.

Referring now toFIGS. 2 and 6, another set of features engageable through the control panel130include filling the and draining transmission pan without removing the pan. In order to perform a quick fill of the transmission pan, the servicing hose46is connected between the exhaust port32and an interrupted influent cooling line or filling port of the transmission. The operator may then select OP1using the options menu button142and depress the start button144to initiate the process. The controller28energizes the dump/supply valve84to the supply position81and actuates the pump24to transfer fluid from the new fluid tank42in a one quart increment to the transmission (FIG. 11).

To drain the transmission pan, the servicing hose44is connected between the return port34and an interrupted effluent transmission cooling line or outlet. OP2is selected by the operator using the options menu button142and the operator may then depress the start button144. Drain/bypass valve70is energized by the controller28to drain position66establishing an open drain path57(FIG. 10). The operator may then turn the vehicle ignition on to start the transmission pump forcing fluid out through the transmission effluent line and into the return port34through the drain path57, in the direction indicated by arrow58, to be collected in the used fluid tank40. Once a quart has been removed as detected by the used fluid level sensor102and determined by the processor28, the complete indicator164on the control board illuminates alerting the operator to terminate the procedure.

Two other options may be used to check the new and used fluid sensors100and102, respectively. To access the new fluid sensor check, the operator may access the options menu132by depressing the options menu button142until OP8is displayed in the counter display136. The operator then depresses the start exchange/options button144. The new fluid level sensor100will transmit a signal to the controller28corresponding to the fluid volume in the new fluid tank42. An absolute reading, which is typically between 300 and 4096 fluid units, will be displayed on the display counter136. The start button144is then depressed again to zero the absolute reading. A measured quantity of new fluid such as one quart is poured into the new fluid tank42through the fill hole. A new reading corresponding to the amount of fluid poured into the new fluid tank is measured by the processor28via the new fluid sensor102and displayed on the counter display136. For example, if one quart is added, the counter display136should read 78 fluid units. Any other reading indicates the sensor may need to be replaced or recalibrated.

A similar procedure may be used to check the used fluid level sensor102. In this scenario, the operator selects OP9in the display counter136using the options menu button142and depresses the start button144. An absolute reading is displayed and then zeroed by depressing the start button144again. A known quantity of fluid is poured into the used fluid tank40which is measured by the used fluid level sensor102and displayed on the display counter102. If the quantity displayed does not correspond to the amount poured in then the operator is alerted that the used fluid sensor may need to be replaced or recalibrated.

Another convenient feature programmed into the controller28is the totalizer. Such feature keeps track of the number of fluid units passing through the servicing apparatus20. The total amount may be displayed in the display counter136. As the display counter may only display a certain number of digits, a separate rollover counter is displayed indicating how many times the counter has reached its numerical limit. For example, if two digits were dedicated to the totalizer display, a display reading of “2” is displayed initially and is followed by a “78”. Such display indicates the servicing apparatus has circulated 278 quarts of fluid. Advantageously, this feature enables the operator to develop a maintenance or replacement plan for the servicing apparatus20and its components. This feature is accessible through depressing the stop button188for approximately 5 seconds.

The capability for smaller increment level adjustments is also conveniently built into the servicing apparatus20. For example, if during an exchange operation, the operator elects to top off the transmission fluid level with the hose46connected between the exhaust port32and the transmission influent line or inlet, the operator may depress the add ATF button182on the control panel130(FIG. 2). In response, the controller28commands the dump/supply valve84to the supply position81and further commands the pump24to actuate such that a predetermined amount of new fluid is transferred along the supply path to the transmission (FIG. 11). It has been found that about 2/10 of a quart is a sufficient amount for such incremental fluid transfers although it will be appreciated that other suitable levels may be used. Once the predetermined amount has been removed from the new fluid tank42, the controller28shuts the pump24off to terminate the transfer.

To withdraw a relatively small increment of used fluid from the transmission, the operator selects the remove ATF button184on the control panel130while the vehicle transmission is running and the hose44is connected between the return port34and the transmission effluent line or outlet (FIGS. 2 and 10). The controller28will then command the drain/bypass valve70to assume the drain position66such that used fluid is transferred from the transmission under the pressure of the transmission pump through the return port34to the used fluid tank40in the direction of arrow58through the drain path57upon turning the vehicle engine on. Once a 2/10 of a quart or other predetermined increment is added to the used fluid tank40, the controller28actuates the valve70to bypass position68to direct the fluid through the bypass/recirculation pathway80.

It will be appreciated that the present embodiment is designed to detect reverse flow without harming the apparatus, transmission, or operator, and to prevent fluid exchange until the fluid flow is conducted in a direction wherein the effluent flow from the transmission passes into the return port34and the influent flow to the transmission comes from the exhaust port32. While such features have been provided in the servicing apparatus20to minimize operator intervention and facilitate maintenance of the servicing apparatus and alert the operator to error conditions, as discussed above, it is contemplated that an operator may on occasion inadvertently couple the service hoses44and46between the transmission and servicing apparatus20incorrectly thus creating a reverse fluid circulation condition. While this may be adequately handled as described above with an alert to the operator, other ways of handling this condition are also contemplated by the present invention.

Cross Flow Operation

As discussed above, it is foreseeable that an operator may inadvertently connect the hoses44and46improperly and upon initiating an exchange procedure, a switch hoses indicator166would illuminate on the control board130to alert the operator to the error condition indicating that fluid is flowing in a direction opposite to direction of arrow59. The operator may then turn the engine off and manually switch the hoses44and46by disconnecting and reconnecting them to the proper return and exhaust ports34and32. The technician may then restart the vehicle and initiate the fluid exchange as described above.

Referring now toFIG. 7, wherein like components are like numbered, a second exemplary embodiment of the present invention includes an alternative manifold body231for avoiding the necessity of manually switching the hoses44and46. In general, this alternative embodiment is constructed the manner as the first manifold body31described above with the exception that an alternative valve270has been substituted in place of the drain/bypass valve70of the first embodiment. Such alternative valve270is preferably a 3-position, 4-way, magnetic solenoid valve with cross flow capabilities. The crossflow valve270includes a normal fluid exchange position, indicated by directional arrows272, a bypass position, indicated by a U-shaped symbol274, and a cross flow fluid exchange position, indicated by directional arrows276.

With continued reference toFIG. 7, when energized to the normal fluid exchange position272by the processor28, used fluid entering the return port34is transferred to the used fluid tank40and new fluid withdrawn from the new fluid tank42may be transferred to the exhaust port32in a manner similar to that described above in the first embodiment. This is effectively the same as the fluid exchange flow along the drain path57and supply path93as in the first embodiment as illustrated inFIGS. 6,9, and11.

If, however, the controller28energizes the alternative valve270to the bypass position274, the servicing apparatus20is placed in a bypass/recirculation mode similar to the recirculation path80illustrated inFIG. 8. Thus fluid may be circulated between the transmission and servicing apparatus as described above with service hoses44and46connected between the return port34, exhaust port32and transmission influent and effluent lines. Fluid being circulated during this mode may circulate in either direction as determined by the flow from the transmission.

Referring now toFIGS. 2,7, and13–14, in those instances where the operator has incorrectly coupled the servicing hoses44and46to the servicing apparatus20so that used fluid enters through the exhaust port32instead of the return port34and the start button144on the control panel130is depressed, the controller28, upon receiving a signal that no fluid is entering the used fluid tank40and detecting fluid pressure via the pressure sensor108, reacts accordingly by energizing the crossflow valve270to assume its cross flow position276. As shown inFIGS. 7 and 14, in this position, it will be appreciated that fluid entering through the exhaust port32will be directed through the solenoid270to cross over to the drain path, generally designated257, to flow in the direction indicated by arrow258, where the used fluid may then be expelled through drain port36to be collected in the used fluid tank40. In such scenario, service hose46is an inhose and port32is an inflow port. Likewise, new fluid supplied from the pump24in the supply path, generally designated293, to flow in the direction indicated by arrow261, and passing through filter88flows through the check valve92and cross over valve270and is directed to the return port34which in this scenario operates as an outflow port and hose44is an outhose (FIGS. 7 and 13). With the solenoid270configured in the cross position276, normal transmission fluid exchange procedures may be performed as described for the first embodiment above. Thus, it will be appreciated that such valve270enables the operator to connect the hoses44and46without concern as to the flow direction as determined by the transmission configuration. Once the controller28establishes the proper valve position272,274, or276, all servicing procedures may be performed as described above for the first embodiment.

While the above described embodiments serve particularly well in servicing automatic transmissions, the present invention further contemplates servicing other automobile fluid systems as well and provides such convenience in a single portable wheeled apparatus.

Power Steering Fluid Servicing

For example, referring now toFIGS. 4–5, another embodiment of the present invention will now be described. When an automobile is taken in for transmission servicing, it is typically necessary and convenient to exchange the power steering fluid at the same time. Advantageously, the present invention may incorporate additional plumbing to facilitate such a power steering fluid exchange.FIG. 4illustrates the additional plumbing for adding fluid to the power steering fluid reservoir (not shown). Such new power steering fluid (PSX) circuit, generally designated200, is a conduit or servicing hose with several inline components including a new power steering fluid tank204preferably having at least a two quart capacity, a new fluid filter206, and a new power steering fluid pump208in fluid communication with one another and terminating at one end in a coupling210or free end for inserting into the open fill hole of the power steering reservoir. An inline ball valve223is provided proximate the hose end to open and close the PSX supply circuit220and prevent residual fluid in the conduit from leaking out inadvertently.

Turning now toFIG. 5, for removing fluid from the power steering reservoir, a PSX drain circuit, generally designated220is also provided. Such drain circuit is a servicing hose or conduit with several inline components including a drain pump222, a used PSX filter224and terminating at one end in a coupling228or free end for insertion into the power steering fluid reservoir. An inline ball valve225is provided for opening and closing the drain circuit for similar purposes to ball valve223. The other end of the PSX drain circuit is conveniently coupled to the used fluid tank40(FIG. 6) so that one common tank may accept either used transmission fluid or used PSX fluid. Such PSX supply pump208and PSX drain pump222are connected to the controller28(FIG. 6) which may actuate either pump. The PSX supply and drain pumps may also be powered by the battery cable120connection to a 12 volt DC power source such as the vehicle battery.

Referring now toFIG. 2, the operator may depress the power steering button180located on the control panel130to initiate a power steering fluid exchange by setting the servicing apparatus20in PSX mode. Alternatively, the power steering exchange may be performed using a remote pendant230having selection switch means including an “ADD” button221and a “DRAIN” button227(FIG. 1). Such pendant may be directly connected to the controller28via suitable electrical cabling or communicate with the controller using wireless technology including radio frequency or infrared communication. It is further contemplated that the ball valves223,225may be coupled to the pendant230and remotely actuatable. Conveniently, when not in use, the pendant is releasably retained on the control panel using a removable magnetic holder229placed on the control board130in the pendant dock region140(FIGS. 1 and 2).

In operation, and with particular attention toFIGS. 1–2,4and5, to exchange the power steering fluid in the power steering fluid reservoir, the following exemplary procedure may be used. The apparatus20is initially wheeled over near the vehicle and the operator attaches the battery cables120to the vehicle battery providing power to the servicing apparatus20and drain and supply pumps208,222. The operator may then depress the power steering button180to set the servicing apparatus20into power steering fluid exchange mode. “PS” will display in the display counter136on the control board130to indicate power steering mode is engaged. The cap of the power steering reservoir, and any screen, is removed. The operator may then start the vehicle ignition to start the engine running. The PSX drain coupling222, which may be an open hose end is placed inside the power steering reservoir as is the supply coupling210, also an open hose end. The hoses are preferably equal in length and are disposed near the bottom of the power steering fluid reservoir and are maintained at all times beneath the top fluid level in the fluid reservoir. Each ball valve223,225, of the respective supply and drain circuits200,220are opened fully. Conveniently, the remote pendant230may be removed from its holder229and held by the operator to extend operator mobility. The magnetic holder may then be used to hold the hoses of the drain and supply conduits in place to prevent the hoses from tangling. With the ball valves223,225open, the operator depresses the Add and Drain buttons221,227on the pendant230alternately to repeatedly drain and fill the reservoir while observing the fluid level in power steering fluid reservoir (FIGS. 1, and4–5). This flushes the old fluid out of the reservoir. With the engine still running, the operator turns the steering wheel fully to the left and right and then back to the center and then checks the fluid color in the reservoir. Using the pendant allows the operator to move between the steering wheel and fluid reservoir. The alternating drain and fill step and wheel turning step are repeated until a satisfactory fluid color is observed. During this process, the processor28monitors the used fluid tank40level via the used fluid sensor102. If a used fluid tank overflow condition is anticipated, the processor28disables the drain button227on the pendant, illuminates the used fluid full indicator172, and sounds an alarm.

Once the operator notes the desired fluid color indicating the exchange is complete, the operator may depress the ADD button221on the pendant to top off the power steering fluid reservoir. Alternatively, the operator may observes bubbles in the power steering fluid reservoir indicating that the new fluid supply has been exhausted. The operator may then turn off the engine off and replace the cap and screen, if any, on the power steering fluid reservoir. Depressing the power steering button180again resets the servicing apparatus to automatic transmission fluid exchange mode. It is apparent that the remote pump actuator conveniently allows the operator to move back and forth between the vehicle steering wheel and the power steering fluid reservoir as necessary.

It will be appreciated that system described herein is capable of performing a number of operations including draining the used ATF fluid from the transmission, adding new ATF fluid to the transmission, draining the used fluid tank, draining the new ATF tank, using a single common pump coupled to a fluid circuit provided by an integrated manifold assembly constructed to minimize assembly time. Additional plumbing features may also be introduced to perform cross flow situations as well as service the power steering reservoir with a servicing apparatus incorporating a minimal amount of components.

The common pump24is preferably a one-way 130 psi pump available from Shur-Flo. The power steering drain and fill pumps208,220are also available from Shur-Flo and of a 45 psi variety. Other suitable pump varieties may also be used. The pressure switch is preferably set to about 6 psi and is available from the Nason Company.

It will be appreciated that the drain path58(FIG. 10) between the return port34and drain port36is formed almost entirely within the manifold body as is the recirculation path59(FIG. 8) between the return port34and exhaust port32. Such paths only exit the manifold body to enter filter60. In addition, much of the dump and supply path61,63, respectively, lengths are formed within the manifold body31as well with only a relatively short segment extending outside the manifold body to pass through the pump24or filter88. Incorporation of a number of right angles in the pathways is formed using three longitudinally projecting bores which are perpendicular from the passages projecting from the ports on the rear and top surfaces of the manifold body31. The bores ends are plugged during manufacture192. By forming most of the fluid circuit within the manifold body, the hose length requirements are significantly reduced and the drawbacks of using hose segments such as those caused by high temperatures are effectively removed as well.

While a rigid manifold body having a preformed fluid circuit has been described in these exemplary embodiments, it is contemplated that such manifold body could also be a hollow or a partially hollow shell incorporating flexible or rigid conduits internally between the various ports.

While the present invention has been described herein in terms of a number of preferred embodiments for performing fluid servicing procedures on a vehicle, various changes and improvements may also be made to the invention without departing from the scope thereof.