Power Steering Pump Service Manual - TRW Aftermarket

1 TRW AutomotiveCommercial Steering SystemsPower Steering PumpService ManualEV SERIESH azard Warning DefinitionsDisclaimerThis Service Manual has been prepared by TRW Commercial Steering Systems forreference and use by mechanics who have been trained to repair and Service steeringcomponents and systems on heavy commercial vehicles. TRW Commercial SteeringSystems has exercised reasonable care and diligence to present accurate, clear andcomplete information and instructions regarding the TRW Commercial Steering EVSeries 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 EV pumpor if you encounter circumstances not covered in the Manual , STOP - CONSULT THEVEHICLE MANUFACTURER'S Service Manual AND WARRANTY.

2 DO NOT TRY TO REPAIR ORSERVICE AN EV Power Steering PUMP WHICH HAS BEEN DAMAGED OR INCLUDES ANYPART THAT SHOWS EXCESSIVE WEAR UNLESS THE DAMAGED AND WORN PARTS AREREPLACED WITH ORIGINAL TRW REPLACEMENT AND Service PARTS AND THE UNIT ISRESTORED TO TRW'S SPECIFICATIONS FOR THE EV Power Steering is the responsibility of the mechanic performing the maintenance, repairs or serviceon a particular EV 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) fully inspectand test the EV 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 TRW Commercial Steering Systems EV Series Power Steering Pump is coveredby several United States and foreign patents, either issued or pending.

3 TRW Inc., 2002A 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 procedure easier of ContentsSection 1 General 4 General Design & Operation .. 5 Torque Chart .. 6 Specification 6 Part Number Breakdown .. 7 Service Parts List .. 8 Exploded View .. 9 Oil Flow Illustration .. 10 Approved Hydraulic Fluids .. 10 Section 2 InstallationInstallation 12 Maintenance 13 Section 3 Reseal & RepairDisassembly Preparation .. 18 Inspection .. 22 Assembly Preparation/Assembly .. 24 Section 4 31 Glossary.

4 32It is imperative that the instructions in this booklet be followed to the to observe the procedures may result in a loss of 1 General InformationIntroduction ..4 General Design & Operation ..5 Torque Numbers ..6 Part Number Parts Flow Hydraulic 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 follow. Pay special attention to the notes,cautions and numbers on the exploded view correspond with item numbers used throughoutthis Service you gain experience in servicing EV Series Power Steering pumps, you may findthat some information in this Service Manual could be clearer and more complete.

5 Ifso, 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 EV Series pumps should be safe and DesignDescription of the EV Series Power Steering PumpThe EV Series Power Steering pump is a balanced, positive displacement, sliding vane type, two line pump with aninternal pilot operated flow control and relief valve. The components of this description are broken down andexplained below:BalancedThe pumping element has two pumping pockets opposed 180 from each other which balance the internal forcesdue to the pressure generated by the pumping DisplacementThe pump will output a fixed volume for each revolution of the input shaft.

6 The fixed volume is determined by theinternal contour of the cam Vane TypeThis describes the type of pumping element. The EV pumping element consists of three The rotor that holds the vanes and is driven by the engine with the pump input The vanes that slide back and forth in slots in the rotor while following the internal contour of thecam ring as the rotor is being turned, thus a sliding The cam ring that contains the internal contour that defines the amount of fluid that is output with eachrevolution of the LineThe EV pump requires an inlet line to supply oil to the pump and an outlet line to take the oil supplied by the pumpto the Steering gear. All excess (bypass) oil is diverted internally in the pump housing back to the inlet of thepumping element.

7 Other systems may have a third line which takes this excess oil back to the flow Control ValveThe pump has a pilot operated valve built into the pump housing that will control the amount of oil that is output tothe Steering gear. This allows the output flow to remain within specification for almost any input speed Valve (if equipped)The pump has a pilot operated relief valve built into the flow control valve spool which will limit the maximumpressure the pump can produce. When the pressure limit has been reached, the relief section will cause the flowcontrol to bypass more oil internal to the pump, limiting the outlet OperationWhat is a Power Steering Pump?The pump is the heart of the hydraulic Steering system.

8 It converts the rotational energy supplied by the engineinto hydraulic energy, flow and pressure, for use by the Steering of OperationAll pumps function by creating a partial vacuum at the inlet, which causes atmospheric pressure to force fluid intothe pump from the reservoir. The pump then pushes this fluid into the system for use. The fluid is used to powerthe Steering gear. Pump output flow relates to Steering gear speed and pump output pressure relates to steeringgear force (work).6 Part NameItem # Torque DryBolts (4)1924 ft lb (33 N m)Relief valve seat assembly3E7 ft lb (9 N m)Plug665 ft lb (88 N m)Pressure port (outlet)37 ft lb maximum (50 N m)Suction port (inlet)74 ft lb maximum (100 N m)Torque ChartSpecification NumbersThe EV 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 input numbers referenced above are shown on the exploded view on page 9.

9 TRW NO. EVXXXXXXXXXXXXSERIAL NO. XXXXX-XXXCUST. NO. XXXXXXXXXXXX7 Part NumberFamily designationDisplacement per revolution18 = 18 cc ( cir)22 = 22 cc ( cir)25 = 25 cc ( cir)28 = 28 cc ( cir)Flow control12 = 12 lpm ( gpm)14 = 14 lpm ( gpm)16 = 16 lpm ( gpm)Relief setting09 = 90 bar (1305 psi)15 = 150 bar (2175 psi)16 = 160 bar (2320 psi)17 = 170 bar (2465 psi)18 = 185 bar (2683 psi)Direction of rotationR = clockwise rotationL = counterclockwise rotationShaft type1 = 11 tooth 16/32 splineHousing01 = SAE A Flange - JIC ports02 = SAE A Flange - Metric portsCustomer version00 = StandardEV 18 12 15 R 1 01 008 ItemDescriptionPart NumberSeal KitSK000255(Includes following parts)2 Shaft seal0328475O-ring seal0328458O-ring seal03285211O-ring seal03285317O-ring seal032851 Grease pack406036 MSDS sheetA10007 Service Parts List9EV Series Exploded View1 Housing2 Shaft seal3 Valve spool assemblya.

10 Spoolb. Springc. Poppetd. Shimse. Relief valve seat assembly4 Spring5 O-ring6 Plug7 Input shaft8 O-ring9 Wave spring10 Pressure plate11 O-ring12 Rotor13 Vanes14 E-ring15 locating pins16 Cam ring17 O-ring18 End cover19 Bolts (4)20 Orifice21 Snap ring12203a3b3c3d3e3456789101112131415161 718192110 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. M2C138 CJMack EO-K2 Engine OilCompletely flush the Steering system with one of the recommended fluids above only. Donot mix oil types. Any mixture or any unapproved oil could lead to seal deterioration andleaks.