lock LEXUS SC400 1991 Service Repair Manual

POWER STEERING SYSTEM BLEEDING
SR0G2±04
1. CHECK FLUID LEVEL IN OIL RESERVOIRCheck the fluid level and add fluid if necessary.
Fluid:
ATF DEXRON
[ II
HINT: Check that the fluid level is within the HOT LEVEL of
the dipstick of the reservoir cap. If the fluid is cold, check that
it is within the COLD LEVEL of the dipstick.
2. START ENGINE AND TURN STEERING WHEEL FROM LOCK TO LOCK 3 OR 4 TIMES
With the engine speed below 1,000 rpm, turn the steering
wheel to left or right full lock and keep it there for 2±3 se-
conds, then turn the wheel to the opposite full lock and keep
it there for 2±3 seconds.
3. CHECK THAT FLUID IN OIL RESERVOIR IS NOT FOAMY OR CLOUDY AND DOES NOT RISE OVER MAXIMUM
WHEN ENGINE IS STOPPED
Measure the fluid level with the engine running. Stop the en-
gine and measure the fluid level.
Maximum rise:
5 mm (0.20 in.)
If a problem is found, repeat fluid replacement on page
SR±114. Rep air the PS if the problem persists.
OIL PRESSURE CHECK
SR0G3±03
1. CONNECT PRESSURE GAUGE
(a) Using SST, disconnect the pressure line joint.SC 400:
SST 09631±22020
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STEERING POWER STEERINGSR±115
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(b) Connect the gauge side of the pressure gauge to the PSpump side, and the valve side to the gear housing side.
2. BLEED POWER STEERING SYSTEM (See page SR±115)
3. START ENGINE AND RUN IT AT IDLE
4. BOOST FLUID TEMPERATURE With the engine idling at 1,000 rpm or less, turn the steering
wheel from lock to lock several times to boost fluid tempera-
ture.
Fluid temperature: 80
C (176
F)
5. CHECK FLUID PRESSURE READING WITH VALVE
CLOSED
Close the pressure gauge valve and observe the reading on
the gauge.
Minimum pressure:
7,355 kPa (75 kgf/cm
2, 1,067 psi)
NOTICE:
w Do not keep the valve closed for more than 10 seconds.
w Do not let the fluid temperature become too high.
If pressure is low, repair or replace the PS vane pump.
6. OPEN VALVE FULLY
7. CHECK AND RECORD PRESSURE READING AT 1,000
RPM
8. CHECK AND RECORD PRESSURE READING AT 3,000 RPM
Check that the pressure difference between the 1,000 rpm
and 3,000 rpm checks is less than 490 kPa (5 kgf/cm
2, 71
psi). If the difference is excessive, repair or replace the flow
control valve of the PS vane pump.
NOTICE: Do not operate the steering wheel.
SR±116±
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9. CHECK PRESSURE READING WITH STEERING WHEELTURNED TO FULL LOCK
Be sure the pressure gauge valve is fully opened and the en-
gine idling.
Minimum pressure:
7,355 kPa (75 kgf/cm
2, 1,067 psi)
NOTICE:
w Do not maintain lock position for more than 10 seconds.
w Do not let the fluid temperature become too high.
If pressure is low, the gear housing has an internal leak and
must be repaired or replaced.
10. MEASURE STEERING EFFORT
(a) Center the steering wheel and run the engine at idle.
(b) Using a spring scale, measure the steering effort in both directions.
Maximum steering effort:
40 N (4.1 kgf, 9.0 lbf)
If steering effort is excessive, repair the power steering unit.
HINT: Be sure to consider the tire type, pressure and contact
surface before making your diagnosis.
(c) Disconnect the solenoid connector.
(d) Using a spring scale, measure the steering effort in both directions.
(Reference)
Maximum steering effort:
76 N (7.7 kgf, 17.0 lbf)
If steering effort is not heavier than (b), check solenoid.
HINT: Be sure to consider the tire type, pressure and contact
surface before making your diagnosis.
±
STEERING POWER STEERINGSR±117
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POWER STEERING PUMP
(SC400)
POWER STEERING PUMP REMOVAL
AND INSTALLATION
SR0G4±01
Remove and install the parts, as shown.
MAIN POINTS OF REMOVAL AND
INSTALLATION
1. REMOVE DRIVE BELTLoosen the drive belt tension by turning the drive belt tension-
er counterclockwise, and remove the drive belt.
SR±118
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STEERING GEAR HOUSING
DISASSEMBLY
SR0GL±02
1. CLAMP GEAR HOUSING IN VISEUsing SST, secure the steering gear in a vise.
SST 09612±00012
2. REMOVE RIGHT AND LEFT TURN PRESSURE TUBES
(a) Remove the union bolt and gaskets.
(b) Using SST, remove the pressure tube. SST 09633±00020
(c) Remove the union seat.
3. REMOVE TIE ROD ENDS
(a) Loosen the lock nut and place matchmarks on the tie rod end
and rack end.
(b) Remove the tie rod end and rack guide spring cap lock nut.
4. REMOVE RACK BOOTS, CLAMPS AND CLIPS
(a) Remove the clip and clamp.
(b) Remove the rack boot.
(c) Mark the left and right boot.
5. REMOVE RACK ENDS AND CLAW WASHERS
(a) Unstake the claw washer.
NOTICE: Avoid any impact to the rack.
SR±150±
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(b) Using SST, remove the rack end.SST 09612±24014 (09617±24011)
09617±14010
(c) Remove the claw washer.
6. REMOVE RACK GUIDE SPRING LOCK NUT
Using SST, remove the rack guide spring cap lock nut.
SST 09612±24014 (09617±24020)
7. REMOVE RACK GUIDE SPRING CAP Using SST, remove the rack guide spring cap.
SST 09612±24014 (09612±10022)
8. REMOVE RACK GUIDE SPRING, RACK GUIDE AND RACK GUIDE SEAT
9. REMOVE RACK HOUSING CAP
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STEERING POWER STEERINGSR±151
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10. REMOVE SELF±LOCKING NUTUsing SST to hold the control valve shaft, remove the self±
locking nut.
SST 09616±00010
11. REMOVE DUST COVER
12. REMOVE CONTROL VALVE HOUSING
(a) Using a hexagon wrench, remove the 2 bolts.
(b) Pull out the valve with the valve housing.
(c) Remove the O±ring from the valve housing.
13. REMOVE CONTROL VALVE Using a plastic hammer, tap out the control valve.
14. REMOVE LOWER BEARING AND SPACER
15. REMOVE CYLINDER END STO PPER, SPACERS, OIL
SEAL AND RACK
(a) Using snap ring pliers, remove the snap ring.
SR±152
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(b) Using SST, press the rack until the end stopper slightlytouches the press block.
SST 09612±24014 (09612±10061)
(c) Slightly tap the rack end with a brass bar and hammer.
(d) Pull out the rack with cylinder end stopper, 2 spacers and oil seal.
16. REMOVE RACK HOUSING OIL SEAL AND SPACER Using SST, tap out the oil seal and spacer.
SST 09631±12020, 09631±20031
GEAR HOUSING COMPONENTS
INSPECTION AND REPAIR
SR0NZ±01
1. INSPECT RACK
(a) Using a dial indicator, check the rack for runout and for teethwear or damage.
Maximum runout:
0.3 mm (0.012 in.)
(b) Check the back surface for wear or damage.If faulty, replace it.
2. IF NECESSARY, REPLACE RACK HOUSING BEARING AND OIL SEAL
(a) Using SST, remove the bearing. SST 09612±30012
NOTICE: Be careful not to damage the rack housing.
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STEERING POWER STEERINGSR±153
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9. INSTALL SELF±LOCKING NUTUsing SST to hold the control valve shaft, install a new self±
locking nut.
SST 09616±00010
Torque: 39 N Vm (400 kgf Vcm, 29 ft Vlbf)
10. INSTALL RACK HOUSING CAP
(a) Apply sealant to 2 or 3 threads of the cap.
Sealant:
Part No. 08833±00080, THREE BOND 1344, LOCTITE
242 for equivalent
(b) Install the cap.
Torque: 69 N Vm (700 kgf Vcm, 51 ft Vlbf)
11. INSTALL RACK GUIDE SEAT, RACK GUIDE AND RACK
GUIDE SPRING
12. ADJUST TOTAL PRELOAD
(a) Apply sealant to 2 or 3 threads of the spring cap.
Sealant: Part No. 08833±00080, THREE BOND 1344, LOCTITE
242 or equivalent
(b) Using SST, install and torque the spring cap.SST 09612±24014 (09612±10022)
Torque: 25 N Vm (250 kgf Vcm, 18 ft Vlbf)
(c) Using SST, return the rack guide spring cap 125
SST 09612±24014 (09612±10022)
(d) Using SST, turn the control valve shaft right and left 1 or 2
times.
SST 09616±00010
(e) Loosen the spring cap until the rack guide compression spring is not functioning.
SR±160
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(f) Using SST and a torque meter, tighten the rack guide springcap until the preload is within specification.
SST 09612±24014 (09612±10022)
09616±00010
Preload (turning):
0.9±1.9 N Vm (9±20 kgf Vcm 7.9±17.3 in. Vlbf)
13. INSTALL RACK GUIDE SPRING CAP LOCK NUT
(a) Apply sealant to 2 or 3 threads of the lock nut.
Sealant:
Part No. 08833±00080, THREE BOND 1344, LOCTITE
242 or equivalent
(b) Using SST, install and torque the lock nut.SST 09612±24014 (09612±10022, 09617±24020)
Torque: 56 N Vm (570 kgf Vcm, 41 ft Vlbf)
HINT: Use a torque wrench with a fulcrum length of 340 mm
(13.39 in.).
(c) Recheck the total preload.
Preload (turning):
0.9±1.9 N Vm (9±20 kgf Vcm 7.9±17.3 in. Vlbf)
14. INSTALL DUST COVER
15. INSTALL CLAW WASHERS AND RACK ENDS
(a) Install new claw washer.
HINT: Align the claws of the claw washer with the rack
grooves.
(b) Using SST, install and torque the rack end. SST 09612±24014 (09617±24011)
09617±14010
Torque: 92 N Vm (940 kgf Vcm, 68 ft Vlbf)
HINT: Use a torque wrench with a fulcrum length of 340 mm
(13.39 in.).
(c) Using a brass bar and hammer, stake the claw washer.
±
STEERING POWER STEERINGSR±161
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