Lexus SC300 / Lexus SC400. Manual - part 324

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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COOLIING SYSTEM

Electronically Controlled Hydraulic
Cooling Fan (Hydraulic Pump)

CO–31

3. 

MOUNT REAR HOUSING
HINT: 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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COOLIING SYSTEM

Electronically Controlled Hydraulic
Cooling Fan (Hydraulic Pump)

(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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COOLIING SYSTEM

Electronically Controlled Hydraulic
Cooling Fan (Hydraulic Pump)

CO–33

12.  REMOVE SPOOL VALVE

(a)  Using a 10 mm hexagon wrench, remove the end plug

and 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
Cooling Fan (Hydraulic Pump)