Lexus RX300 (MCU15). Service manual - part 510

SR05N–04

SR–2

–

STEERING

TROUBLESHOOTING

LEXUS RX300   (RM785E)

TROUBLESHOOTING

PROBLEM SYMPTOMS TABLE

Use the table below to help you find the cause of the problem. The numbers indicate the priority of the likely
cause of the problem. Check each part in the order shown. If necessary, repair or replace these parts.

Symptom

Suspect Area

See page

Hard steering

11.Tires (Improperly inflated)

12.Power steering fluid level (Low)

13.Drive belt (Loose)

14.Front wheel alignment (Incorrect)

15.Steering system joints (Worn)

16.Suspension arm ball joints (Worn)

17.Steering column (Binding)

18.Power steering vane pump

19.Power steering gear

SA–2

SR–6

SR–3

SA–4

–

SA–37

–

SR–20

SR–31

Poor return

1. Tires (Improperly inflated)

2. Front wheel alignment (Incorrect)

3. Steering column (Binding)

4. Power steering gear

SA–2

SA–4

–

SR–31

Excessive play

1. Steering system joints (Worn)

2. Suspension arm ball joints (Worn)

3. Intermediate shaft, Universal joint (Worn)

4. Front wheel bearing (Worn)

5. Power steering gear

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SA–37

–

SA–10

SR–31

Abnormal noise

1. Power steering fluid level (Low)

2. Steering system joints (Worn)

3. Power steering vane pump

4. Power steering gear

SR–6

–

SR–20

SR–31

P06717

SR1CB–01

F10520

Compressor

Clankshaft

Altenator

PS Vane Pump 
Pulley

98 N (10 kgf, 22 lbf)

P06723

CORRECT

WRONG

WRONG

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STEERING

DRIVE BELT

SR–3

LEXUS RX300   (RM785E)

DRIVE BELT

INSPECTION

INSPECT DRIVE BELT
(a)

Visually check the drive belt for excessive wear, frayed
cords etc.

If any defect has been found, replace the drive belt.
HINT:
Cracks on the rib side of a drive belt are considered acceptable.
If the missing chunks from the ribs are found on the drive belt,
it should be replaced.

(b)

Measure the drive belt deflection.
Drive belt tension: at 98 N (10 kgf, 22 lbf)
New belt: 7 – 9 mm (0.28 – 0.35 in.)
Used belt: 10 – 12 mm (0.39 – 0.47 in.)

If the belt defection is not as specified, adjust it.

HINT:

S

”New belt” refers to a belt which has been used less than
5 minutes on a running engine.

S

”Used belt” refers to a belt which has been used on a run-
ning engine for 5 minutes or more.

S

After installing a belt, check that it fits properly in the
ribbed grooves.

S

Check with your hand to confirm that the belt has not
slipped out of the groove on the bottom of the pulley.

S

After installing a new belt, run the engine for about 5 min-
utes and recheck the belt tension.

Z11352

SR–4

–

STEERING

DRIVE BELT

LEXUS RX300   (RM785E)

S

Reference: 
Using a belt tension gauge, measure the drive belt ten-
sion.
Drive belt tension:
New belt: 690 – 780 N (70 – 80 kgf)
Used belt: 350 – 490 N (35 – 50 kgf)

If the belt tension is not as specified, adjust it.

SR05P–12

R11741

Normal

Abnormal

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STEERING

POWER STEERING FLUID

SR–5

LEXUS RX300   (RM785E)

POWER STEERING FLUID

BLEEDING

1.

CHECK FLUID LEVEL (See page SR–6)

2.

JACK UP FRONT OF VEHICLE AND SUPPORT IT
WITH STANDS

3.

TURN STEERING WHEEL

With the engine stopped, turn the steering wheel slowly from
lock to lock several times.
4.

LOWER VEHICLE

5.

START ENGINE

Run the engine at idle for a few minutes.
6.

TURN STEERING WHEEL

(a)

With the engine idling, turn the steering wheel to left or
right full lock position and keep it there for 2 – 3 seconds,
then turn the wheel to the opposite full lock position and
keep it there for 2 – 3 seconds.

(b)

Repeat (a) several times.

7.

STOP ENGINE

8.

CHECK FOR FOAMING OR EMULSIFICATION

If the system has to be bled twice specifically because of foam-
ing or emulsification, check for fluid leaks in the system.
9.

CHECK FLUID LEVEL (See page SR–6)