LEXUS SC400 1991 Service Repair Manual

2. INSPECT OIL PRESSUREHINT: Before inspecting the oil pressure, first check that the
A/C is off.
(a) Using SST, connect terminals OP1 and E1 of the check(ºDIAGNOSISº) connector.
SST 09843±18020
HINT: When terminals OP1 and E1 are connected, the circuit
of the water temp. sensor is grounded, fixing the fan speed
at approx. 1,100 rpm. (Fail±safe operation occurs.)
(b) Bleed the hydraulic cooling system
(See page CO±24)
(c) Keep the engine speed at 2,000 rpm until the fluid temperature reaches the specified temperature.
Fluid temp.: 70±90 5C (158±195 5F)
(d) Check the fluid level is correct.
(e) Measure the oil pressure at idling.
Oil pressure: 1,177±2,452 kPa
(12±25 kgf/cm, 171±356 psi)
(f) Remove the SST from the check connector.
SST 09843±18020
(g) Check that the oil pressure decreases.
3. REMOVE PRESSURE GAUGE, AND CONNECT PRESSURE HOSE
Torque: 64 N Vm (650 kgf Vcm, 47 ft Vlbf)
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COOLIING SYSTEM Electronically Controlled Hydraulic
Cooling Fan (On±Vehicle Inspection)CO±25
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Hydraulic Pump
COMPONENTS FOR REMOVAL AND
INSTALLATION
CO±26±
COOLIING SYSTEM Electronically Controlled Hydraulic
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REMOVAL OF HYDRAULIC PUMP
(See Components on page CO±26)
1. REMOVE BATTERY CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the ºLOCKº position and the negative (±) termi-
nal cable is disconnected from the battery.
2. REMOVE ENGINE UNDER COVER
3. DRAIN ENGINE COOLANT (See page CO±6)
4. REMOVE DRIVE BELT Loosen the drive belt tension by turning the drive belt tension-
er counterclockwise, and remove the drive belt.
HINT: The pulley bolt for the belt tensioner has a left±hand
thread.
5. DISCONNECT A/C COMPRESSOR (a) Disconnect the A/C compressor connector.
(b) Remove the nut, and disconnect the ground cable.
(c) Remove the bolt and A/C compressor stay.
(d) R e m o v e t h e t w o b o l t s , a n d d i s c onnect the A/C
compressor from the engine.
6. REMOVE LH IGNITION COIL (a) Disconnect the following connectors and cord:(1) Ignition coil connector
(2) Noise filter connector
(3) High±tension cord
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COOLIING SYSTEM Electronically Controlled Hydraulic
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(b) Remove the two bolts and ignition coil.
7. REMOVE INTAKE AIR CONNECTOR (a) Disconnect the following hoses:(1) Air hose from ISC valve
(2) Air hose (from PS air control valve) from intake air
connector
(b) Remove the bolt holding the intake air connector to the cylinder head cover.
(c) Loosen the two hose clamps.
(d) Disconnect the intake air connector from the throttle
body and air cleaner hose, and remove the throttle body.
8. REMOVE UPPER HIGH±TENSION CORD COVER (a) Remove the two mounting bolts.
(b) Disconnect the front side claw groove of the cord coverfrom the claw of the lower cover, and remove the cord
cover.
9. REMOVE RH ENGINE WIRE COVER Remove the bolt and engine wire cover.
CO±28
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10. REMOVE LH ENGINE WIRE COVERRemove the two bolts and engine wire cover.
11. REMOVE VSV FOR EVAP SYSTEM Remove the two bolts, and disconnect the VSV from cylinder
head and timing belt cover.
12. REMOVE RH NO.3 TIMING BELT COVER Remove the three bolts and timing belt cover.
13. REMOVE LH NO.3 TIMING BELT COVER (a) Remove the four mounting bolts.
(b) Disconnect the cord grommet from the timing belt cover,
and remove the timing belt cover.
(c) Remove the cord grommet from the high±tension cord.
14. DISCONNECT RADIATOR HOSE FROM WATER INLET
15. REMOVE DRIVE BELT IDLER PULLEY Remove the pulley bolt, cover plate and idler pulley.
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15. REMOVE RH NO.2 TIMING BELT COVER(a) Disconnect the cam position sensor connector from theignition coil bracket.
(b) Disconnect the cam position sensor wire from the clamp
on the timing belt cover.
(c) Remove the five mounting bolts.
(d) Disconnect the wire clamp from the timing belt cover,
and remove the timing belt cover and four gasket.
16. REMOVE LH NO.2 TIMING BELT COVER (a) Disconnect the cam position sensor wire from the clamp
on the timing belt cover.
(b) Disconnect the cam position sensor connector.
(c) Remove the three mounting bolts.
(d) Disconnect the connector grommet from the timing belt cover, and remove the timing belt cover and two
gaskets.
17. DISCONNECT PRESSURE AND SUCTION HOSES FROM HYDRAULIC PUMP
18. REMOVE HYDRAULIC PUMP (a) Disconnect the solenoid valve connector.
(b) Remove the two mounting bolts and two nuts.
(c) Disconnect the engine speed sensor wire clamp.
(d) Remove the hydraulic pump.
CO±30
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COMPONENTS FOR DISASSEMBLY AND
ASSEMBLY
DISASSEMBLY OF HYDRAULIC PUMP
1. REMOVE SUCTION PORT UNION(a) Remove the mounting bolt.
(b) Pull out the port union.
(c) Remove the O±ring from the port union.
2. REMOVE WIRE CLAMP (a) Disconnect the wire clamp from the rear housing.
(b) Remove the wire clamp from the read wire.
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3. MOUNT REAR HOUSINGHINT: Mount the parts in a vise as shown in the illustration.
4. REMOVE SOLENOID VALVE (a) Remove the solenoid valve.
(b) Remove the O±ring from the solenoid valve.
(c) Remove the O±ring from the rear housing.
5. REMOVE PUMP PULLEY (a) Using SST, remove the pulley nut by turning it clockwise.
SST 09278±54012
(b) Using SST, remove the pulley.
SST 09286±46011
6. REMOVE FRONT HOUSING (a) Remove the five mounting bolts.
CO±32
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(b) Using a plastic±faced hammer, carefully tap out the front
housing.
(c) Remove the O±ring from the casing.
7. REMOVE FRONT THRUST WASHER AND DRIVE SHAFT
8. REMOVE DRIVE AND DRIVEN ROTORS
9. REMOVE REAR THRUST WASHER
10. REMOVE CASING (a) Remove the casing.
(b) Remove the O±ring from the rear housing.
11. REMOUNT REAR HOUSING HINT: Mount the parts in a vise as shown in the illustration.
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12. REMOVE SPOOL VALVE(a) Using a 10 mm hexagon wrench, remove the end plugand following parts:
(1) Spool valve
(2) Compression spring
(3) Spool sleeve
(b) Remove the O±ring from the end plug.
INSPECTION OF HYDRAULIC PUMP
1. CLEAN DISASSEMBLED PARTS Using a cleaner and compressed air, clean the disassembled
parts.
CAUTION: Thoroughly clean the oil passages of the rear
housing. Oil passage A includes a filter which should be
cleaned carefully.
2. INSPECT SPOOL VALVE (a) Coat the spool valve with PS fluid, and check that it falls
smoothly into the spool sleeve by its own weight.
(b) Check the spool valve for leakage. Close one of the holes and apply compressed air
392±490 kPa (4±5 kgf/cm2, 57±71 psi) into the opposite
side, check that air does not come out of the end hole.
If it doesn't, replace the spool valve and sleeve as a set.
3. INSPECT SPOOL COMPRESSION SPRING Using a vernier calipers, measure the free length of the com-
pression spring.
Free length: 45.8 mm (1.803 in.)
If the free length is not as specified, replace the compression
spring.
CO±34
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