Lexus RX300 (MCU15). Manual - part 511

SR05Q–13

R11740

HOT

COLD

R11741

Normal

Abnormal

R11786

Engine Idling

Engine Stopped

5 mm (0.20 in.)
or less

SR–6

–

STEERING

POWER STEERING FLUID

LEXUS RX300   (RM785E)

INSPECTION

1.

CHECK FLUID LEVEL

(a)

Keep the vehicle level.

(b)

With the engine stopped, check the fluid level in the oil
reservoir.

If necessary, add fluid.

Fluid: ATF DEXRON

® II or III

HINT:
Check that the fluid level is within the HOT LEVEL range on the
reservoir. If the fluid is cold, check that it is within the COLD
LEVEL range.
(c)

Start the engine and run it at idle.

(d)

Turn the steering wheel from lock to lock several times to
boost fluid temperature.
Fluid temperature: 80

°C (176°F)

(e)

Check for foaming or emulsification.

If there is foaming or emulsification, bleed power steering sys-
tem (See page SR–5).

(f)

With the engine idling, measure the fluid level in the oil
reservoir.

(g)

Stop the engine.

(h)

Wait a few minutes and remeasure the fluid level in the oil
reservoir.
Maximum fluid level rise: 5 mm (0.20 in.)

If a problem is found, bleed power steering system (See page
SR–5).
(i)

Check the fluid level.

F03844

Attachment

Attachment

IN

OUT

Pressure Feed Tube

SST

Z15498

Oil
Reservoir

PS Vane
Pump

PS Gear

SST

Closed

–

STEERING

POWER STEERING FLUID

SR–7

LEXUS RX300   (RM785E)

2.

CHECK STEERING FLUID PRESSURE

(a)

Disconnect the pressure feed tube (See page SR–34).

(b)

Connect SST to pressure feed tube, as shown in the il-
lustration below.
SST

09640–10010 (09641–01010, 09641–01020,
09641–01030)

NOTICE:
Check that the valve of the SST is in the open position.

(c)

Bleed the power steering system (See page SR–5).

(d)

Start the engine and run it at idle.

(e)

Turn the steering wheel from lock to lock several times to
boost fluid temperature.
Fluid temperature: 80 

°C (176 °F)

(f)

With the engine idling, close the valve of the SST and ob-
serve the reading on the SST.
Minimum fluid pressure:
7,845 kPa (80 kgf/cm

2

, 1,138 psi)

NOTICE:

S

Do not keep the valve closed for more than 10 se-
conds.

S

Do not let the fluid temperature become too high.

Z15499

Oil
Reservoir

PS Vane
Pump

PS Gear

SST

Open

Z15500

Oil
Reservoir

PS Vane
Pump

PS Gear

SST

Open

Lock Position

SR–8

–

STEERING

POWER STEERING FLUID

LEXUS RX300   (RM785E)

(g)

With the engine idling, open the valve fully.

(h)

Measure the fluid pressure at engine speeds of 1,000 rpm
and 3,000 rpm.
Difference fluid pressure:
490 kPa (5 kgf/cm

2

, 71 psi) or less

NOTICE:
Do not turn the steering wheel.

(i)

With the engine idling and valve fully opened, turn the
steering wheel to full lock position.
Minimum fluid pressure:
7,845 kPa (80 kgf/cm

2

, 1,138 psi)

NOTICE:

S

Do not maintain lock position for more than 10 se-
conds.

S

Do not let the fluid temperature become too high.

(j)

Disconnect the SST.
SST

09640–10010 (09641–01010, 09641–01030,
09641–01060)

(k)

Connect the pressure feed tube (See page SR–50).

(l)

Bleed the power steering system (See page SR–5).

F05634

Maximum
Freeplay

30 mm
(1.18 in.)

SR05R–14

F05635

–

STEERING

STEERING WHEEL

SR–9

LEXUS RX300   (RM785E)

STEERING WHEEL

INSPECTION

1.

CHECK STEERING WHEEL FREEPLAY

(a)

Stop the vehicle and face the tires straight ahead.

(b)

Rock the steering wheel gently up and down with a finger
lightly, check the steering wheel freeplay.
Maximum freeplay: 30 mm (1.18 in.)

2.

CHECK STEERING EFFORT

(a)

Center the steering wheel.

(b)

Remove the steering wheel pad (See page SR–12).

(c)

Start the engine and run it at idle.

(d)

Measure the steering effort in both directions.
Steering effort (Reference): 
5.9 N·m (60 kgf·cm, 52 in.·lbf)

HINT:
Take the tire type, pressure and contact surface into consider-
ation before making your diagnosis.
(e)

Torque the steering wheel set nut.
Torque: 36 N·m (370 kgf·cm, 27 ft·lbf)

(f)

Install the steering wheel pad (See page SR–18).