Power Steering Pump Service Manual - TRW Aftermarket

1 TRW AutomotiveCommercial Steering SystemsPower Steering PumpService ManualPS SERIESDie CutDesign Features1 Cover rotatable in 90 degree increments2 Heavy duty bearing package3 Lightweight aluminum housing (overall weight lbs.)4 Flow control valve compatible with TAS Steering gear Made in the USA Three inlet port locations Two outlet port locations Three displacements available in a single housingsize Only two housing castings needed Short pump overall length Seals are all high temperature capable (not toexceed 250 F.)4312 Hazard Warning DefinitionsA warning describes hazards or unsafe practices which could result insevere personal injury or caution describes hazards or unsafe practices which could result inpersonal injury or product or property note gives key information to make following a procedureeasier or Service Manual has been prepared by TRW Commercial Steering Division forreference and use by mechanics who have been trained to repair and Service steeringcomponents and systems on heavy commercial vehicles.

2 TRW Commercial SteeringDivision has exercised reasonable care and diligence to present accurate, clear andcomplete information and instructions regarding the TRW Commercial Steering PSSeries Power Steering Pumps. Since this is a general Service Manual , the photo-graphs and illustrations may not look exactly like the pump being serviced. Theprocedures, therefore , must be carefully read and understood before inspection or testing reveals evidence of abnormal wear or damage to the PS pumpor if you encounter circumstances not covered in the Manual , STOP - CONSULT THEVEHICLE MANUFACTURER'S Service Manual AND WARRANTY. DO NOT TRYTO REPAIR OR Service A PS Power Steering PUMP WHICH HAS BEEN DAM-AGED OR INCLUDES ANY PART THAT SHOWS EXCESSIVE WEAR UNLESS THEDAMAGED AND WORN PARTS ARE REPLACED WITH ORIGINAL TRW REPLACE-MENT AND Service PARTS AND THE UNIT IS RESTORED TO TRW'S SPECIFICA-TIONS FOR THE PS Power Steering is the responsibility of the mechanic performing the maintenance, repairs or serviceon a particular PS Power Steering pump to (a) inspect the pump for abnormal wear anddamage, (b) choose a repair procedure which will not endanger his/her safety, thesafety of others, the vehicle, or the safe operation of the vehicle, and (c)

3 Fully inspectand test the PS pump and the vehicle Steering system to ensure that the repair orservice of the pump has been properly performed and that the pump and system willfunction Commercial Steering Division PS Power Steering Pumps are covered by severalUnited States and foreign patents, either issued or pending. TRW Inc., 2006!WARNINGCAUTION!NOTEC ontentsSection 1 General InformationIntroduction .. 6 General Design & Operation .. 7 Oil Flow Illustration .. 8 Approved Hydraulic Fluids .. 8 Torque Chart .. 9 Pump Specification Numbers .. 9 Service Parts List .. 10 Exploded View .. 11 Part Number Breakdown .. 12 Section 2 Initial InstallationInstallation.

4 14 Maintenance Tips .. 15 Section 3 Reseal & RepairDisassembly .. 17 Inspection .. 23 Assembly .. 25 Internal Damage Repair (by reference)Input shaft Replacement .. 31 Needle Bearing Removal .. 32 Section 4 ReinstallationReinstallation .. 34 Filling and Air Bleeding the System .. 35 Maintenance Tips .. 36 Section 5 GlossaryGlossary .. 38 All Steering mechanisms are safety critical items. As such, it is imperative that the instructions in this booklet be followed to the letter. Failureto observe the procedures set forth in this pamphlet may result in a loss of !WARNINGS ection 1 General InformationIntroduction .. 6 General Design & Operation.

5 7 Oil Flow Illustration .. 8 Approved Hydraulic Fluids .. 8 Torque Chart .. 9 Pump Specification Numbers .. 9 Service Parts List .. 10 Exploded View .. 11 Part Number Breakdown .. 12 General InformationIntroductionThe three-column format used in the Service Manual will help make it easy for you toservice a Power Steering pump. Column 1 illustrates the procedure with photographs,column 2 gives a brief key as well as tools to be used for each procedure, and column3 explains in detail the procedure you should special attention to the notes,cautions and exploded view is on a fold-out page so you can see it while reading through theprocedures.

6 Item numbers on the exploded view correspond with item numbers usedthroughout the Service you gain experience in servicing PS Power Steering pumps, you may find thatsome information in this Service Manual could be clearer and more complete. If so,let us know about it. Don't try to second-guess the Service Manual ; if you do notunderstand a procedure, or are stuck, contact our Field Service Department at 1-800-TRW-0899. Servicing PS Power Steering pumps should be safe and DesignDescription of the TRW Commercial SteeringDivision Power Steering PumpThe PS Power Steering pump is a balanced, positivedisplacement, sliding vane type, two line pump with aninternal pilot operated flow control and relief valve.

7 Thecomponents of this description are broken down andexplained below:BalancedThe pumping element has two pumping pockets opposed180 from each other which balance the internal forcesdue to the pressure generated by the pumping DisplacementThe pump will output a fixed volume for each revolutionof the input shaft. This fixed volume is determined by theinternal contour of the cam Vane TypeThis describes the type of pumping element. The PSpumping element consists of three The rotor that holds the vanes and is driven bythe engine with the pump input The vanes that slide back and forth in slots in therotor while following the internal contour of thecam ring as the rotor is being turned, thus asliding The cam ring that contains the internal contourthat defines the amount of fluid that is outputwith each revolution of the LineThe PS pump requires an inlet line to supply oil to thepump and an outlet line to take the oil supplied by thepump to the Steering gear.

8 All excess, (bypass), oil isdiverted internally in the pump housing back to the inletof the pumping element. Other systems may have a thirdline which takes this excess oil back to the Flow Control ValveThe pump has a pilot operated valve built into the pumphousing that will control the amount of oil that is output tothe Steering gear. This allows the output flow to remainwithin specification for almost any input speed ValveThe pump has a pilot operated relief valve built into theflow control valve spool which will limit the maximumpressure the pump can produce. When the pressure limithas been reached, the relief section will cause the flowcontrol to bypass more oil internal to the pump, limitingthe outlet OperationWhat is a Power Steering Pump?

9 The pump is the heart of the hydraulic Steering system. Itconverts the rotational energy supplied by the engine intohydraulic energy, flow and pressure, for use by thesteering of OperationAll pumps function by creating a partial vacuum at theinlet, which causes atmospheric pressure to force fluidinto the pump from the reservoir. The pump then pushesthis fluid into the system for use. The fluid is used topower the Steering gear. Pump output flow relates tosteering gear speed and pump output pressure relates tosteering gear force (work).Approved Hydraulic FluidsAutomatic Transmission Fluid Dexron IIAutomatic Transmission Fluid Type "E" or "F"Chevron 10W-40 Chevron Custom 10W-40 Motor OilChevron Torque 5 FluidExxon Nuto H32 Hydraulic FluidFleetrite PSF (Can #990625C2)Ford Spec.

10 M2C138 CJCompletely flush the Steering system with one of the recommendedfluids above only. Do not mix oil types. Any mixture or any unapprovedoil could lead to seal deterioration and leaks. A leak could ultimately cause the loss of fluid,which could result in a loss of Power Steering Flow IllustrationMack EO-K2 Engine OilMobil ATF 210 Mobil Super 10W-40 Motor OilTexaco 10W-40 Texaco TL-1833 Power Steering FluidUnion 10W-40 Union 15W-40 Unocal Guardon 15W-40 Motor OilThe Steering system should be kept filled with one of the above fluids.!WARNINGI nlet PressureBoost PressureOutlet PressureSeal DrainPilot PressurePart NameItem #Torque Range DryTorque Range LubricatedBolts (4)420-30 lbf ft (27-41 N M) relief valve seat assembly6E7-15 lbf ft (9-20 N M)Plug915-25 lbf ft (20-34 N M)Pressure port (outlet)37 lbf ft maximum (50 N M)Suction port (inlet)74 lbf ft maximum (100 N M)Torque ChartSpecification NumbersThe PS Power Steering pump TRW part number,serial number, and customer part number arestamped on a machined surface located on thebottom of the pump, opposite the valve numbers referenced are shown on the explodedview, pages 7A & NO.