LEXUS SC400 1991 Service Repair Manual

POWER STEERING PUMP
DISASSEMBLY
SR0G7±02
1. MOUNT POWER STEERING PUMP IN VISE
NOTICE: Do not tighten the vise too tight.
2. REMOVE PUMP PULLEY
(a) Using SST, remove the pulley set nut.SST 09278±54012
(b) Remove the pulley.
3. REMOVE SUCTION PORT UNION
(a) Remove the 2 bolts and union.
(b) Remove the O±ring from the union.
4. REMOVE PRESSURE PORT UNION, FLOW CONTROL
VALVE AND SPRING
(a) Remove the pressure port union.
(b) Remove the O±ring from the union.
(c) Remove the flow control valve and spring.
5. REMOVE SPRING SEAT
(a) Using snap ring pliers, remove the snap ring. HINT: The snap ring is easier to remove if the spring seat is
pressed down slightly.
(b) Temporarily install a bolt to the seat and pull out it. HINT: Use a bolt with diameter 6 mm (0.24 in.) and pitch 1.0
mm (0.039 in.).
(c) Remove the O±ring from the seat.
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6. REMOVE VANE PUMP SHAFT WITH BEARING
(a) Using snap ring pliers, remove the snap ring.
(b) Temporarily install the appropriate plate washer and pulleynut to the pump shaft.
(c) Using SST, pull out the pump shaft.
SST 09910±00015 (09911±00011, 09912±00010)
7. REMOVE REAR BRACKET
(a) Remove the 4 bolts and rear bracket.
(b) Remove the O±ring from the bracket.
8. REMOVE WAVE WASHER
9. REMOVE SIDE FRONT PLATE, CAM RING, ROTOR, VANE
PLATES AND SIDE REAR PLATE
(a) Using an extension bar and press, remove the side front
plate, cam ring, rotor, vane plates and side rear plate as an
assembly.
HINT: Catch the assembly in your hand to prevent it dropping.
SR±122
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(b) Remove the side rear plate.
(c) Remove the O±ring from side rear plate.
(d) Remove the cam ring, rotor and the 10 vane plates.
(e) Remove the straight pin from the side front plate.
(f) Remove the 2 O±rings from the side front plate.
(g) Remove the straight pin from the front housing.HINT: Place a workshop rag over the pin to prevent damaging
it.
POWER STEERING PUMP INSPECTION
SR0G8±02
1. MEASURE OIL CLEARANCE OF SHAFT AND BUSHINGUsing a micrometer and calipers, measure the oil clearance.
Standard clearance:
0.01±0.03 mm (0.0004±0.00012 in.)
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Maximum clearance:0.07 mm (0.0028 in.)
If more than maximum, replace the entire power steering
pump.
2. INSPECT ROTOR AND VANE PLATES
(a) Using a micrometer, measure the height, thickness and length of the vane plates.
Minimum height:
8.0 mm (0.315 in.)
Minimum thickness: 1.77 mm (0.0697 in.)
Minimum length:
14.97 mm (0.5894 in.)
(b) Using a feeler gauge, measure the clearance between therotor groove and vane plate.
Maximum clearance:
0.03 mm (0.0012 in.)
If more then maximum, replace the vane plate and/or rotor
with one having the same mark stamped on the cam ring.
Inscribed mark:1, 2, 3, 4 or None
HINT: There are 5 vane lengths with the following rotor and
cam ring marks:
 Rotor and camring number Vane length mm (in.)
 None 14.996±14.998 (0.59039±0.59047) 1 14.994±14.996 (0.59031±0.59039) 2 14.992±14.994 (0.59023±0.59031)
 3 14.990±14.992 (0.59016±0.59024)
 4 14.988±14.990 (0.59007±0.59016)
3. INSPECT FLOW CONTROL VALVE
(a) Coat the valve with power steering fluid and check that it falls smoothly into the valve hole by its own weight.
SR±124
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(b) Check the flow control valve for leakage.Close one of the holes and apply compressed air 392 ±490
kPa (4±5 kgf/ cm
2, 57±71 psi) into the opposite side, and con-
firm that air does not come out from the end holes.
If necessary, replace the valve with one having the same let-
ter as inscribed on the front housing.
Inscribed mark:
A, B, C, D, E or F
4. INSPECT FLOW CONTROL SPRINGUsing a calipers, measure the free length of the spring.
Minimum spring length:
36 mm (1.42 in.)
If not within specification, replace the spring.
5. IF NECESSARY, REPLACE OIL SEAL
(a) Using SST, tap out the oil seal. SST 09631±10030
(b) Using a 22 mm socket wrench and hammer, drive in a new oil seal.
NOTICE: Make sure you install the oil seal facing the correct
direction.
(c) Coat the oil seal lip with power steering fluid.
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6. IF NECESSARY, REPLACE BEARING
(a) Using snap ring pliers, remove the snap ring.
(b) Using a press, press out the bearing.
(c) Using a press, press in a new bearing.
(d) Using snap ring pliers, install a new snap ring.
POWER STEERING PUMP ASSEMBLY
SR0G9±02
1. COAT WITH POWER STEERING FLUID BEFOREASSEMBLY
(See page SR±120)
2. INSTALL VANE PUMP SHAFT WITH BEARING
(a) Using SST and a press, press in the pump shaft. SST 09238±47012
(b) Using snap ring pliers, install a new snap ring.
3. INSTALL SIDE FRONT PLATE, CAM RING, ROTOR, VANE PLATES AND SIDE REAR PLATE
(a) Install the longer straight pin to the front housing.
SR±126
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(b) Coat new 2 O±rings with power steering fluid and install themto the side front plate.
(c) Coat a new O±rings with power steering fluid and install it to the side rear plate.
(d) Using SST and a press, press in the side front plate. SST 09238±47012
HINT: Match the wide hole on the side front plate with the
longer straight pin.
NOTICE: Be careful not to damage the O±rings.
(e) Install the shorter straight pin to the side front plate.
(f) Match the wide hole of the cam ring with the longer straightpin, and install the cam ring.
HINT: Install the cam ring with the inscribed mark facing the
rear.
(g) Install the rotor to the shaft with the inscribed mark facing the rear.
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(h) Coat the 10 vane plates with power steering fluid.
(i) Install the 10 vane plates with the round end facing outward.
(j) Match the wide hole with the longer straight pin and press inthe side rear plate with a press.
NOTICE: Be careful not to damage the O±ring.
4. INSTALL WAVE WASHERInstall the wave washer so that its protrusions fit into the slots
in the side rear plate.
5. INSTALL REAR BRACKET
(a) Coat a new O±ring with power steering fluid and install it to the rear bracket.
(b) Install the rear bracket and tighten the 4 bolts.
Torque: 39 N Vm (400 kgf Vcm, 29 ft Vlbf)
SR±128±
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6. MEASURE PUMP SHAFT PRELOAD
(a) Check that the shaft rotates smoothly without abnormalnoise.
(b) Temporarily install the pulley nut and check the rotating
torque.
Rotating torque:
0.1 N Vm (1.0 kgf Vcm, 0.9 in. Vlbf) or less
7. INSTALL FLOW CONTROL VALVE, SPRING, SPRING
SEAT AND PRESSURE PORT UNION
(a) Coat new O±rings with power steering fluid and install them
to the spring seat and pressure port union.
HINT: Install a thick O±ring to the spring seat and a thin O±
ring to the pressure port union.
(b) Install the spring seat with the bolt hole facing out±ward.
(c) Using snap ring pliers, install a new snap ring.
(d) Install spring and valve to the front housing.
(e) Install and torque the pressure port union.
Torque: 69 N Vm (700 kgf Vcm, 51 ft Vlbf)
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8. INSTALL SUCTION PORT UNION
(a) Coat a new O±ring with power steering fluid and install it tothe suction port union.
(b) Install the suction port union with the 2 bolts.
Torque: 13 N Vm (130 kgf Vcm, 9 ft Vlbf)
9. INSTALL PUMP PULLEY
(a) Install the pulley and nut to the shaft.
(b) Using SST, torque the set nut.
SST 09278±54012
Torque: 43 N Vm (440 kgf Vcm, 32 ft Vlbf)
SR±130±
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