Patent Publication Number: US-2005133304-A1

Title: Fluid exchange system for vehicles

Description:
RELATED APPLICATIONS  
      This application is a continuation-in-part of application Ser. No. 10/026,137, filed Dec. 18, 2001, now U.S. Pat. No. 6,667,633, which was a continuation of application Ser. No. 08/772,836, filed Dec. 24, 1996, now U.S. Pat. No. 6,330,934, which was a continuation of application Ser. No. 08/469,673, filed Jun. 6, 1995, and which was a continuation-in-part of application Ser. No. 08/209,061 filed Mar. 9, 1994, granted U.S. Pat. No. 5,472,064, and now U.S. Reissue Pat. No. RE36,650, which was a continuation-in-part of application Ser. No. 07/781,322 filed Oct. 23, 1991, now U.S. Pat. No. 5,318,080, each related application being incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION  
      This invention relates generally to changing the fluid of vehicular automatic transmissions and/or power steering circuits and more specifically to a fluid exchange system providing bypass flow and/or flow alignment capabilities.  
     SUMMARY OF THE INVENTION  
      A fluid exchange system having a first fluid line selectively intercoupled to the fluid exchange system and one of a pair of fluid circuit ports to conduct fluid from a fluid circuit of a vehicle and a second fluid line selectively intercoupled to the fluid exchange system, a source of fresh fluid, and the other one of the pair of fluid circuit ports to conduct fluid into the fluid circuit of the vehicle. The fluid exchange system also includes a bypass fluid path and a bypass valve assembly in communication with the bypass fluid path, said fluid exchange system having a pair of operational conditions including: a first operational condition wherein used fluid is passed through the bypass fluid path and reintroduced into the fluid circuit of the vehicle, and a second operational condition wherein used fluid is received into the first fluid line and fresh fluid is received into the second fluid line and introduced into the fluid circuit of the vehicle. The bypass valve may be actuated via mechanical, electromechanical, or hydraulic means. The fluid exchange system can be used to service both automatic transmission systems and power steering systems. 
    
    
     DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a representative illustration of the applicant&#39;s system as it is typically positioned with respect to a vehicle being serviced.  
       FIG. 2  is a schematic illustration an embodiment interconnected to a vehicular automatic transmission to be serviced by the invention.  
       FIG. 3  is a schematic illustration an embodiment interconnected to a vehicular automatic transmission or power steering system to be serviced by the invention.  
       FIGS. 4 and 5  are schematic illustrations a power steering circuit of a vehicle to be serviced by the invention. 
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION  
       FIG. 1  is a representative illustration of a fluid exchange system  20  as it may be positioned relative to a vehicle  7  being serviced. Fluid exchange system  20  is interconnected into the automatic transmission system via a pair of interchangeable input/output hoses (an input/output hose  4  and an input/output hose  5 ) to vehicle  7  being service.  
      In the illustrated embodiment of  FIG. 1 , hoses  4  and  5  are connected to an accessed transmission cooling circuit of vehicle  7  which connects to and runs through a transmission cooler  11  which may be an integral part of a radiator  13 . Hose  4 ,  5  connection may be done by making random connection to a pair of quick connect stems (a quick connect stem  10  and a quick connect stem  12 ) which have been interconnected to the cooling circuit. A used fluid receptacle  21  is used to receive the used fluid extracted from transmission  9  by the fluid exchanger  20 . A fresh fluid receptacle  23  is used to supply the fresh fluid which is introduced into transmission  9  during an exchange mode of operation. A control panel  25  is located on the fluid exchange system  20  to provide indications of operation and/or control.  
       FIG. 2  is an illustration of a first embodiment of the fluid exchange system  20  which is randomly interconnected to both sides of an opened fluid cooling circuit  27 / 11 / 29 , designated as  27 / 11 / 29  because before being opened it is comprised of a cooling outlet line  27 , a transmission fluid cooler  11  inside a radiator  13  and a cooling return line  29 , each of which form together a connected, complete cooling circuit of transmission  9 . Input/output hoses  4 ,  5  are shown interconnected to both sides of cooling circuit  27 / 11 / 29 . Hose  4  is connected to line  29  at connector  30 , through stem  10  which is connected to hose  4  by quick connector  14 . Stem  10  is connected to the end of line  29  at connector  30  after connector  30  has been disconnected from a port  28  of cooler  11  (as an alternative choice, a port  26  of cooler  11  can be disconnected for the interconnection location if preferred by the operator). Hose  5  is connected to line  27  through stem  12  which is connected to hose  5  by quick connector  16  which is connected to opened port  28  of cooler  11 , thereby connecting hose  5  to a transmission cooler  11  located in radiator  13 . Input/output hoses  4  and  5  are connected to two different ports of a flow alignment valve  45 . Valve  45  may be a manually and/or electrically actuated valve or valves. Valve  45  may be a  4  port, two position, electrically actuated fluid valve as illustrated in  FIG. 2 .  
      Used fluid receptacle  21  has an opening with a closure  97  and a vent tube  95 . Receptacle  21  has volume level indicating marks numbered in quarts (not shown). A used fluid delivery line  92  connects one port of a bypass valve  49  to an used fluid receptacle  21 . Bypass valve  49  in one embodiment is a combination, multi-port, two-position flow direction selector valve. Bypass valve  49  may comprise a plurality of valves, passages and/or conduits. Bypass valve  49  may be electrically operated, such as via a solenoid. Alternatively, bypass valve  49  may be manually operated, such as by an operator. Additionally, bypass valve  49  may be float-actuated whereby a float within fresh fluid receptacle  23  and/or within used fluid receptacle  21  may be used to control position of bypass valve  49 . For example, a float within fresh fluid receptacle  23  may be used to place the exchange system  20  in a bypass mode of operation when the fresh fluid level drops to a predetermined level. The float may be mechanically linked to bypass valve  49  and/or may be electrically coupled to an intermediate electronic controller. Float mechanisms for fluid control are disclosed in applicant&#39;s copending application Ser. No. 10/241,734, hereby incorporated by reference in its entirety.  
      A fluid delivery line  47  connects one port of bypass valve  49  to one port of flow alignment valve  45 . Fresh fluid receptacle  23  is connected to a suction tube  69  which is in turn connected by a quick connector  73  to a fresh fluid suction line  71  which is connected to a suction port  70  of a main pump  65 . An opening with closure  76  and a vent tube  78  is provided to fresh fluid receptacle  23 . Receptacle  23  has volume indicating marks present similar to used fluid receptacle  21 , but reversed to illustrate quarts of used fluid deposited (marks not shown).  
      Main pump  65  can be activated by an electric power supply switch  67 , and when activated pumps fresh fluid through an outlet port  64 , into a fresh fluid delivery line  63  and through adjustable flow regulator  61 . A fresh fluid delivery line  59  connects regulator  61  to a combination rate of flow and total volume of flow indicator/meter  57  which indicates rate of flow and volume of fresh flow delivered. Fresh fluid delivery line  51  connects meter  57  to bypass valve  49 . A fluid delivery line  47  connects one port of bypass valve  49  to one port of flow alignment valve  45 .  
      A used fluid delivery line  83  connects one port of bypass valve  49  to a bidirectional combination indicator/meter  77  which indicates direction of used flow, rate of used flow, and total volume of used flow. A used fluid delivery line  75  connects meter  77  to one port of flow alignment valve  45 . A three port used fluid bypass fluid path  85  connects two ports of bypass valve  49  with a sample tap  87 . Bypass fluid path  85  may comprises a flexible fluid line, a fluid passage-way through a fluid manifold, or other fluid passages as appreciated by those of ordinary skill in the art.  
      Prior to use of exchange system  20 , used fluid receptacle  21  may be emptied through an opening with closure  97  after disconnecting connector  41  and then reconnected to connector  41  so that an empty receptacle is available to receive the used fluid extracted from the transmission  9  being serviced. Fresh fluid receptacle  23  may be filled through an opening in closure  76  while in place, or receptacle  23  can be removed by disconnecting it at connector  73  to fill it, and then replacing it in position and reconnecting connector  73 . In heavy duty or fleet applications, it may be useful to connect the invention to receptacles much larger than receptacles  21  and  23 , such a bulk containers.  
      As an example, connection of the system  20  to the transmission system is performed by the following steps. The cooling circuit  27 / 11 / 29  is opened at port  28  where line  29  is connected to cooler  11 . The operator&#39;s selection of the location to open cooling circuit  27 / 11 / 29  at port  28  is random and made at the preference of the operator as a matter of ease and convenience. There may be other access locations at which circuit  27 / 11 / 29  is suitable for opening, including connection  26 , ports at the transmission body, or intermediate connections of the lines defining conduits  27 ,  29 . In such a manner, system  20  may access the hydraulic system of the transmission system of the vehicle  7 .  
      Stem  12  is connected to the outlet side of the opened cooling circuit by connecting it to port  28  of cooler  11  and stem  10  is connected to the inlet side of the opened cooling circuit by connecting it to connector  30  of cooling return line  29 . Input/output hoses  4 ,  5  can be randomly connected to the opened cooling circuit  27 / 11 / 29 , but in this illustration for sake of example input/output hose  4  is connected to cooling return line  29  through stem  10 , and input/output hose  5  is connected to cooling outlet line  27  thought cooler  11  and stem  12 .  
      The fluid exchange system  20  can now be operated. The vehicle is started and run with the transmission in park and the fluid level of pan  19  may be checked and corrected if out of the range desired. In a bypass mode of operation with bypass valve  49  in a bypass condition, used fluid contained in transmission  9  is recirculated through exchange system  20  via conduits  4 ,  5 . In the bypass mode of operation, flow alignment valve  45  may be used to correct the flow of fluid within the bypass valve  45  and conduits  47 ,  75  relative to the flow of fluid flowing within cooling conduits  27 ,  29 . Alignment of the fluid flow within conduits  47 ,  75  via alignment valve  45  may be made with reference to a flow direction meter  77 . Meter  77  may be a visual and/or electronic meter indicating flow direction of fluid within conduit  75 .  
      In a bypass mode of operation, used fluid from hose  5  flows from meter  77  through conduit  83  to bypass valve  49 , through bypass valve  49  and into bypass fluid path  85  and back through valve  49  to line  47 , through line  47  to alignment valve  45 , through alignment valve  45  to input/output hose  4 , and through quick connector  14 , through stem  10  and into cooling return line  29  which carries the used fluid back into transmission  9 . In bypass mode of operation, the used fluid is recirculated back to the transmission  9  without substantial introduction or exchange of fresh fluid. Bypass mode of operation may take place before, during or after the fluid exchange procedure as described hereinafter. Bypass mode may be entered via mechanical actuation of bypass valve  49 . Mechanical actuation of valve  49  may be via operator manipulation or via a float mechanism. One such float mechanism may include a float within fresh fluid reservoir  23  which moves in response to a fluid level. The float may be used to mechanically move bypass valve  49  or may provide a signal to an electronic controller which, in response to a float signal, activates the valve  49 . Bypass mode may also be entered via electrical actuation of bypass valve  49  in response to other signals, such as start flow or stop flow control signals.  
      Flow alignment valve  45  may be controlled in response to the direction of flow indicated at meter  77 . In the illustrated embodiments, flow alignment valve  45  is a two position flow direction selector valve which switches direction of flow between lines connecting valve  45  and bypass valve  49 , thus providing the capability to randomly connect the input/outlet hoses  4 ,  5  to either side of opened cooling circuit  27 / 11 / 29 . Alignment valve  45  permits quick alignment of the direction of flow in cooling circuit  27 / 11 / 29  with the direction of flow in the two main subsystems, the used fluid extraction subsystem and the fresh fluid introduction subsystem which are contained in the fluid exchange system  20 . In the embodiment illustrated in  FIG. 2 , valves  45  and valve  49  are mechanically operated. In other embodiments valves  45 ,  49  may be electrically operated, microprocessor controlled, and/or electronically indicating.  
      Valves  45 ,  49  as depicted in  FIG. 2  are illustrated in most basic form for simplicity of illustration. Various other more dispersed variants comprised of multiple solenoid or manually operated sub-units can be utilized which operate under the same principle of art when examined in unity, but do not vary from the actual scope of what is illustrated in this embodiment.  
      If the used fluid is flowing through cooling circuit  27 / 11 / 29  such that when randomly connected to the invention with valve  49  in its Off/bypass mode (dotted line) meter  77  indicates that the flow is not in alignment with the invention. Flow alignment valve  45  may then be actuated to its second, alternate position which institutes a flow alignment condition which is then indicated at meter  77 .  
      Meter  77  electronically and/or visually indicates proper flow alignment, and may also indicate the rate of flow at which the used fluid is being circulated through cooling circuit  27 / 11 / 29  as bypassed through bypass fluid path  85  and the operator makes note of this.  
      When bypass valve  49  is in its Off/bypass position (as indicated by dotted lines), the used fluid passes only through the valve ports connected to both sides of bypass fluid path  85 . At this point, the operator may use sample tap  87  to draw a sample of the used fluid circulating in the cooling circuit into a clear sample vial to later give to the vehicle&#39;s owner.  
      In an exchange mode of operation, bypass valve  49  is placed in a secondary or On position (as indicated with solid lines) which allows the fresh fluid forced into line  63  by pump  65  to flow through flow regulator  61  through line  59  to flow meter  57 , through line  51  to the main valve  49  to line  47 , through line  47  to alignment valve  45 , through alignment valve  45  and to input/output hose  4  and then into the return cooling line  29 . As the fresh fluid then flows through the fresh fluid introduction subsystem of the invention and into the return side of the opened cooling circuit, it then flows to the internal transmission components downstream to the return side of the cooling circuit and eventually comes to rest in transmission  9 . As fresh fluid so flows, the operator (or an electronic controller) adjusts flow regulator  61  such that the rate of flow of fresh fluid approximately matches the flow rate at which used fluid was measured at meter  77  to have been circulating at in the cooling circuit when the invention was in bypass mode with the transmission operating in park. After so operating the invention for a period of time necessary to exchange the contents of the transmission system, the operator may activate bypass valve  49  by moving its selector to the alternate Off/bypass position. At this point, pump  65  may still be activated but not delivering fresh fluid into transmission  9  because main valve  49  now has closed fresh fluid delivery line  51 . The operator can examine the volume indicating marks on fresh receptacle  23  which will indicate the amount fresh fluid was used in the exchange procedure.  
      Input/output hoses  4 ,  5  can then be disconnected at quick connectors  14 ,  16 . Stems  10 ,  12  can then disconnected from both sides of the opened cooling circuit at port  28  and connection  30 . Cooling return line  29  is then reconnected to port  28  at connection  30  to close the previously opened cooling system  27 / 11 / 29 .  
      The vehicle is now started with the transmission in park and the operator checks the cooling circuit for any leaks should the connections not be secure. The operator then checks the fluid level of the transmission by use of the dipstick (not shown) inserted in dipstick/filler tube.  
      In other embodiments of the exchange system  20 , a microprocessor can be used to control valves  45 ,  49  and other system controls. The microprocessor may receive electronic indicating signals from electronically indicating sensors and meters, the process the signals according to software instructions and then elicit electronic command signals to individual components which are electronically controlled and electrically powered. The selection of a specific wiring harness, microprocessor parts, circuits and connectors, etc. would be within the skill of a person of ordinary skill in the relevant art.  
      Referring now to  FIG. 3 , another embodiment of an automotive fluid servicing apparatus, generally designated  120 , incorporating aspects of the present invention is illustrated. In general, such fluid servicing apparatus is incorporated into a convenient, portable wheeled cabinet housing 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 pump  124  and an integrated conduit system as directed by a service technician and controlled by a processor/controller  128 .  
      System  120  includes an exhaust port  132 , a return port  134 , a drain port  136 , and a fresh fluid supply port  138 . Each port may be 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.  
      A used fluid conduit  139  connects between the drain port  136  and a used fluid collection tank  140  to carry fluid therebetween. Similarly, the fresh fluid supply port  138  connects via a new fluid supply conduit  141  to a new fluid tank  142 . Such used fluid collection tank  140  is constructed to hold a sufficient amount of used fluid to accommodate at least complete drain procedure and preferably more. The new fluid tank  142  is 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 source  142  may be filled through a fill hole  145 . As it is preferred that the servicing apparatus maintain a portable capability, the used and new fluid tanks are preferably mounted inside the cabinet which is sized to accommodate the preferred tank capacities.  
      Further convenience is provided by a set of servicing hoses,  144  and  146  respectively for connecting between the return port  134  and the exhaust port  132  of the servicing apparatus  120  and the influent line and effluent line of the serviceable component such as an automatic transmission or power steering unit of an automobile. The use of conventional adapters is also contemplated if necessary. The connectors illustrated in  FIG. 3  are 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 or power steering system in fluid communication with the servicing apparatus  120  as will be discussed below.  
      A number of pathways are defined within system  120  as well as a number of flow control components for routing fluid entering and exiting the system between the various fluid ports  132 ,  134 ,  136 , and  138 . In this exemplary embodiment, there are at least three such pathways including a drain path, generally designated  157 , for flow of fluid as indicated by directional arrow  158 , a recirculation path, generally designated  180 , for flow of fluid as indicated by directional arrow  159 , and a supply path, generally designated  193 , for fluid flow as indicated by directional arrow  161 . Each pathway  157 ,  180 , and  193  include couplings or connectors of flexible or rigid material connected to one or more manifold ports.  
      During a fluid exchange procedure as will be discussed below, fluid is normally directed in the direction of arrow  158  through the drain path  157  from the return port  134  to the used fluid drain port  136  which may be connected to the used fluid collection tank  140  via conduit  139 . Valve  170  includes a exchange position which directs fluid entering the inlet of the valve  170  out of a drain outlet of the valve  170  and through the remainder of the drain path  158  and a bypass position which directs fluid entering the inlet of the valve  170  out of an alternate outlet and through a recirculation path  180 .  
      When the drain/bypass valve  170  is energized to the bypass position, the recirculation path  180  is opened and the drain path  157  is blocked. Fluid entering the recirculation path from the return port  134  is directed through the valve  170  set in the bypass position  168  to exhaust port  132 . Such recirculation path normally serves to circulate fluid in the direction indicated by arrow  159  between the serviceable component and the servicing apparatus while bypassing the pump  124 , used fluid tank  140 , and new fluid tank  142 .  
      With continued reference to  FIG. 3 , fluid typically enters the return port  134  from conduit  144  connected to the downstream port of the transmission and exits the exhaust port  132  to be directed through hose  146  to the upstream port of the transmission  200  or power steering circuit  202 . Fluid is generally circulated through the fluid circuit by the pump  124 . Direction of the fluid through the fluid circuit is normally determined by the respective positions of the drain/bypass valve  70  and the flow alignment valve  184 . The drain/bypass valve  170  operates to direct fluid entering the return port  134  through the drain or bypass passages  157  and  180  respectively with one side of the valve  170  in fluid communication with the return port  134  and the second side in fluid communication with the drain port  136  and exhaust port  134 . When valve  170  enters into the drain position the bypass passage  180  is blocked off and the passage between the return port  134  and the drain port  136  is open and fluid may flow in the direction of arrow  158 . On the other hand, when the valve  170  is energized to the bypass position, the drain passage  157  is blocked off and the passage between the return port  134  and the exhaust port  132  is open establishing a bypass loop  180  wherein fluid may circulate in the direction of the arrow  159  and wherein fluid does not circulate through the pump  124 .  
      The heart of the electrical command sub-system is the controller  128  which is a programmable circuit board having a central processing unit (CPU) and associated memory for transmitting control commands to the pump  124  or valves  170 ,  184  in 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.  
      The controller  128  is connected to a new fluid tank sensor  204  and a used fluid tank sensor  206  through their respective electrical leads to provide fluid level feedback for each tank,  142  and  140 , respectively. The fluid level sensors detect the fluid level in their respective fluid tanks and provide this information to the controller.  
      The pump  124 , drain/bypass valve  170 , and flow alignment valve  184  are in electrical communication with the controller  128  via their respective electrical connectors. Using feedback from the sensors and any additional operator input, the controller energizes the bypass and flow alignment valves  170  and  184  to the desired positions as will be described below and further actuates the pump  124  to on and off states during selected servicing procedures to circulate the fluid through the fluid circuit from the desired source to the selected destination.  
      When the service technician is prepared to service an automobile transmission, with reference to  FIG. 3 , the new fluid tank  142  and used fluid tank  140  may initially be empty. The servicing apparatus  120  is initially prepped for servicing by filling a quantity of new transmission fluid through a fill hole (not shown) into the new fluid tank  142 . For purposes of this operational procedure, it will be assumed that the used fluid tank  140  is initially empty and the new tank  142  has an adequate supply of transmission fluid to perform a complete exchange. The servicing apparatus  120  is 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 ports  134  and  132  using the service hoses  144  and  146  using conventional adapters if necessary. Preferably, the technician connects the effluent line of the transmission to the return port  134  and further connects the influent line at one end to the exhaust port  132  such that the connection places the transmission in fluid communication with the fluid passages  157 ,  180  and  193  of the servicing apparatus  120 . If through inadvertence or error the technician connects the effluent line of the transmission to the exhaust port  132  and further connects the influent line at one end to the return port  134 , the flow alignment valve  184  may be selectively activated to correct the alignment of flows within the apparatus  120 . It will be appreciated that the service hoses  44 ,  46  may be clear allowing an operator to visually check the condition of the fluid in each hose. The default position of the drain/bypass valve  170  is the bypass position blocking off the drain path  157  so that fluid flow from the transmission will circulate through fluid passage  180  in the direction of arrow  159  initially when the vehicle engine is turned on to activate the transmission pump.  
      Using the versatile servicing apparatus  120 , 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 a pump  124  operating in conjunction with the vehicle transmission pump for some procedures.  
      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 recirculation passage  180 . This is commonly referred to as bypass or recirculation mode. Depending on the transmission pump and direction of fluid flow, used fluid from the transmission is forced out into either the return port  134  or the exhaust port  132 . Fluid will either flow in the direction of arrow  159  or in a reverse direction. The fluid exits the recirculation passage  180  from the opposite port wherein fluid is entering and reenters the transmission through the associated servicing hose. At this point a closed circulation loop between the vehicle transmission cooling lines and servicing apparatus  120  is established.  
      The operator presses the start button on the control panel of the servicing apparatus  120 , which causes several actions to occur. Initially, the controller  128  energizes the drain/bypass valve  170  to move from the bypass position to the drain position to block off the recirculation passage  180  and open the drain path  157 . If the service hoses have been connected so as to provide flow alignment between the system  120  and the accessed fluid circuit, used fluid entering the return port  134  under pressure from the transmission pump is directed through the drain path  157 , along the direction of arrow  158 , through the drain port  136  and used fluid conduit  139  connected thereto to be collected in the used fluid collection tank  140 . If the service hoses have been connected in an opposite manner, flow alignment valve  184  may be activated to correct fluid flow within the system  120 .  
      When the start button is pressed the transmission pump will force the fluid from the return port  134  into the drain passage  157  and through the valve  70  set in the drain position. Used fluid passing through the valve  170  is directed to the drain port  136  in the direction of arrow  158  and expelled into the used fluid tank  140 .  
      While such features have been provided in the servicing apparatus  120  to 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 hoses  144  and  146  between the transmission and servicing apparatus  120  incorrectly thus creating a reverse fluid circulation condition.  
      An exemplary embodiment of the present invention includes a flow alignment valve  184  for avoiding the necessity of manually switching the hoses  144  and  146 . Flow alignment valve  184  is preferably a 2-position, 4-way valve with cross flow capabilities. The crossflow valve  184  includes a normal fluid exchange position and a cross flow fluid exchange position, indicated by directional arrows  208 . Thus, it will be appreciated that such valve  170  enables the operator to connect the hoses  144  and  146  without concern as to the flow direction as determined by the transmission configuration. Once the controller  128  establishes the proper valve position, all servicing procedures may be performed as described above.  
      When energized to the normal fluid exchange position by the processor  128 , used fluid entering the return port  134  is transferred to the used fluid tank  140  and new fluid withdrawn from the new fluid tank  142  may be transferred to the exhaust port  132  in a manner similar to that described above in 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. For example, when an automobile is taken in for transmission servicing, it is typically desirable and convenient to exchange the power steering fluid at the same time. The fluid exchange systems of the present invention may be advantageously utilized to service both automatic transmission and power steering systems of an automobile.  
       FIG. 4  depicts one of the two basic types of power steering systems found in vehicles today, commonly referred to as a traditionally configured power steering system which has its fluid reservoir arranged integral to the power steering pump as a reservoir-pump combination assembly. With this configuration the pump supply conduit from the reservoir to the intake port of the pump is very short in length and is hidden from view inside the reservoir-pump combination assembly. Typically a power assisted steering gear mechanism accompanies this configuration. The power steering system of FIG. 4  has a reservoir  300  arranged integral to a power steering pump  305  to form a combination reservoir-pump assembly  392 . Reservoir  300  contains a fluid  301 . A reservoir outlet conduit  306  carries fluid  301  from reservoir  300  to an inlet port  307  of pump  305 . Typically, this configuration includes a steering gear mechanism  312 . A pressure conduit  310  connects an outlet port  309  of pump  305  to an inlet port  311  of steering gear mechanism  312 , which is power assisted by the pressurized fluid provided by pump  305  through pressure conduit  310 . The fluid in pressure conduit  310  has higher pressure than the fluid located anywhere else in the power steering system and this pressurized fluid is the working fluid which provides the power to assist the driver in steering the vehicle. Thus fluid  301  is pressurized by pump  305  to provide power to do the hydraulic work required to make the vehicle easier to steer by the driver. Steering gear mechanism  312  has a fluid return conduit  314  with hose end  315  attached by a ferrule  320  which may be crimped. Fluid return conduit  314  is connected to an outlet port  313  of steering gear mechanism  312 . Hose end  315  is connected to a reservoir return port  316  and sealingly secured by a hose clamp  317 , which is a stainless steel gear drive type. Power is provided to pump  305  by a belt  319  which is rotated around a pulley  318  under power of the engine of the vehicle (not shown). Reservoir  300  has a filler neck  302  which receives and holds a cap  303  which is vented to the atmosphere. Cap  303  has a dipstick  304  integral to its bottom side. Fluid  301  is delivered from reservoir  300  under power of pump  305  to be circulated out of port  309  through pressure conduit  310  into port  311 , through steering gear mechanism  312 , out of outlet port  313 , through conduit  314  and hose  315 , into and through port  316  to be deposited back into reservoir  300  for redundant delivery and circulation by pump  305 .  
       FIG. 5  depicts the second of two basic types of power steering systems found in vehicles today, commonly referred to as a more modern power steering system which has its fluid reservoir arranged at a remote location above the power steering pump with the pump supply conduit and the low pressure outlet conduit from the power assisted steering mechanism typically visible and accessible, with each conduit connected to one of the two ports of the remote reservoir. A power assisted rack and pinion steering mechanism typically accompanies this second type of system. As with the more traditionally configured system having a reservoir-pump combination, the low pressure fluid return conduit from the power assisted steering mechanism is connected to the return port of the reservoir. In addition the fluid reservoir is typically translucent, allowing one to note the fluid level through the wall of the reservoir at designated marks on the wall. This power steering system has a fluid reservoir  400  arranged at a remote location above a power steering pump  405  which contains a fluid  401 . Reservoir  400  has two visible and typically accessible ports, a reservoir outlet port  406  and a reservoir return port  416 . A pump supply hose  408  connects reservoir outlet port  406  to a pump inlet port  407 . Pump supply hose  408  is sealingly secured to port  406  and to port  407  by a pair of hose clamp  417 . A pressure conduit  410  connects a pump outlet port  409  of pump  405  to an inlet port  411  of a rack and pinion steering mechanism  412 , which is power assisted by the fluid power provided by pump  405 . Fluid  401  is pressurized by pump  405  to provide power to do the hydraulic work required to make the vehicle easier to steer by the driver. Rack and pinion steering mechanism  412  has a fluid return conduit  414  with a hose end  415  attached by a ferrule  420  which may be crimped. Fluid return conduit  414  is connected to an outlet port  413  of rack and pinion steering mechanism  412 . Hose end  415  is connected to reservoir return port  416  and sealingly secured by hose clamp  417 . Power is provided to pump  405  by a belt  419  which is rotated around a pulley  418  under power of the engine of the vehicle (not shown). Reservoir  400  has a filler neck  402  which receives and holds a cap  403  which is vented to the atmosphere. In normal operation the power steering system is constructed and arranged for fluid  401  to be delivered from reservoir  400  through port  406 , through pump supply hose  408  into pump inlet port  407  under power of pump  405  to be circulated out of pump outlet port  409  into and through pressure conduit  410  and through inlet port  411 , through rack and pinion steering assembly  412 , out of outlet port  413 , through fluid return conduit  414  and hose end  415 , and into and through reservoir return port  416  to be deposited into reservoir  400  for redundant delivery and circulation by pump  405 .  
      The automotive fluid servicing apparatus of the present invention may be utilized to exchange power steering fluid of a vehicle. For example, the fresh fluid tank  142  may hold fresh power steering fluid and the used fluid tank  140  may receive used fluid during an exchange procedure. In a manner similar to the transmission exchange procedure, the service hoses  144 ,  146  may be intercoupled into a power steering fluid circuit. For example, and with reference to  FIG. 5 , service hoses  144 ,  146  may be coupled to pump supply hose  408  and fluid return conduit  414 . Alternatively, one of the service hoses  144 ,  146  may simply be inserted into the fluid reservoir  400  so that fresh power steering fluid freely flows from the hose  144 ,  146  into the reservoir  400 . In such an application, the reservoir return port  416  may be capped to prevent fluid flow. Additional access locations may exist within the power steering circuit which permit introduction of the power steering servicing apparatus  120 . The features of flow alignment and/or bypass may also find practical use in a power steering servicing apparatus according to the present invention. For example, a flow alignment valve may be utilized to change the flow of fluid with the exchange system to correct for inadvertent misconnection of the fluid exchange system into the power steering hydraulic circuit. Additionally, a bypass valve may be utilized to isolate portions of the fluid exchange system during periods of the overall exchange process.  
      While my above description contains many specifics, these should not be construed as limitations on the scope of the invention, but rather as exemplification of two embodiments thereof. For example, there are many similar ways to illustrate certain of the device&#39;s valve and indicator functions as numerous single entity components organized in more complex fashion while functioning in the same overall manner as illustraed in my figures and described in my specifications. These variants should not be construed as significantly different from the novel art presented in my specifications or claims byt should be consudered as a part of this same novel art my device is based on. These many possible small changes and alternative methods to express the same principles of the novel art of my device are not important enough to illustrate in the drawings. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.