Lexus SC300 / Lexus SC400. Manual - part 746

(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 BUSHING
Using a micrometer and calipers, measure the oil clearance.

Standard clearance:

0.01–0.03 mm (0.0004–0.00012 in.)

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SR–123

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 the

rotor 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:

ÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑ

Rotor and cam

ring number

ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ

Vane length     mm (in.)

ÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑ

None

ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ

14.996–14.998 (0.59039–0.59047)

ÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑ

1

ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ

14.994–14.996 (0.59031–0.59039)

ÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑ

2

ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ

14.992–14.994 (0.59023–0.59031)

ÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑ

3

ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ

14.990–14.992 (0.59016–0.59024)

ÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑ

4

ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑÑ

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 SPRING
Using 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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SR–125

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 BEFORE

ASSEMBLY
(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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