1991 LEXUS SC300 oil

BLEEDING OF HYDRAULIC COOLING
SYSTEM
1. CHECK FLUID LEVEL IN RESERVOIR TANKIf low, add fluid.
Fluid: ATF DEXRON II
HINT: Check that fluid level is within the ºHOTº level on reser-
voir tank. If the fluid is cold, check that it is within the ºCOLDº\
level on the tank.
2. BLEED COOLING SYSTEM (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) Start the engine without depressing the accelerator pedal.
(c) Leave the engine running for several seconds.
(d) Check that there is no foaming and emulsification of the fluid in the reservoir tank.
INSPECTION OF OIL PRESSURE
1. CONNECT PRESSURE GAUGE
(a) Remove the union bolt and gasket, and disconnect thepressure hose from the hydraulic motor.
(b) Connect the gauge side of a pressure gauge to pressure
hose, and the valve side to the hydraulic motor.
CO±24
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COOLIING SYSTEM Electronically Controlled Hydraulic
Cooling Fan (On±Vehicle Inspection)
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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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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
Cooling Fan (Hydraulic Pump)CO±27
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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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COOLIING SYSTEM Electronically Controlled Hydraulic
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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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COOLIING SYSTEM Electronically Controlled Hydraulic
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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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COOLIING SYSTEM Electronically Controlled Hydraulic
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5. INSPECT OIL CLEARANCE OF DRIVE SHAFT(a) Using a caliper gauge, measure the bushing insidediameter on the housing.
Bushing inside diameter: 17.00±17.05 mm
(0.6693±0.6713 in.)
(b) Using a micrometer, measure the drive shaft diameter.
Shaft diameter: 16.97±16.98 mm(0.6681±0.6685 in.)
(c) Subtract the drive shaft diameter measurement from the
bushing inside diameter measurement.
Standard clearance: 0.02±0.08 mm
(0.0008±0.0031 in.)
Maximum clearance: 0.08 mm (0.0031 in.)
If the clearance is greater than maximum, replace the shaft.
If necessary, replace the housings.
6. INSPECT SOLENOID VALVE RESISTANCE Using an ohmmeter, measure the resistance between the ter-
minals.
Resistance (Cold): 7.5±8.5

CO±36±
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REPLACEMENT OF OIL SEAL
1. REMOVE OIL SEALUsing SST and a hammer, tap out the oil seal.
SST 09631±10030
2. INSTALL OIL SEAL (a) Using a 22 mm socket wrench and hammer, tap in a new
oil seal until its surface is flush with the housing edge.
(b) Apply fluid to the oil seal lip.
ASSEMBLY OF HYDRAULIC PUMP
(See Components on page CO±31)
HINT:
w Thoroughly clean all parts to be assembled.
w Before installing the parts, apply new fluid to all sliding
and rotating surfaces.
1. MOUNT REAR HOUSING HINT: Mount the parts in a vise as shown in the illustration.
2. INSTALL SPOOL VALVE (a) Align the small hole of the spool sleeve with the hole ofthe rear housing, and insert the spool body into the rear
housing.
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COOLIING SYSTEM Electronically Controlled Hydraulic
Cooling Fan (Hydraulic Pump)CO±37
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