Mitsubishi Montero (2004+). Manual - part 1154

POWER STEERING DIAGNOSIS

TSB Revision

POWER STEERING

37A-5

STEP 2. Check the belt for damage.
Q: Is the belt damaged?

YES : Replace the belt. Then go to Step 10.
NO :  Go to Step 3.

STEP 3. Check the fluid level.
(1)  Park the vehicle on a flat, level surface, start the engine, 

and then turn the steering wheel several times in both 

directions to raise the temperature of the fluid to 
approximately 50 

− 60°C (122 − 140°F).

(2)  With the engine running, turn the wheel all the way to the 

left and right several times.

(3) Check the fluid in the oil reservoir for foaming or milkiness. 

Check the difference of the fluid level when the engine is 
stopped, and while it is running. If the change of the fluid 
level is 5 mm (0.2 inch) or more, bleed air from the system 
(Refer to 

P.37A-17

).

Q: Is fluid foamy?

YES : Go to Step 4.
NO :  Go to Step 10.

STEP 4. Check for entry of air.
Q: Has air entered?

YES : Bleed the air. Refer to 

P.37A-18

. Then go to Step 10.

NO :  Go to Step 5.

STEP 5. Check each hose for crushing or twisting.
Q: Is any hose crushed or twisted?

YES : Repair or replace the hose. Then go to Step 10.
NO :  Go to Step 6.

STEP 6. Check for oil leaks.
Q: Are there oil leaks?

YES : Repair it. Then go to Step 10.
NO :  Go to Step 7.

STEP 7. Check the wheel alignment (camber and caster).

Refer to GROUP 33A, On-vehicle Service 

− Front Wheel Align-

ment Check and Adjustment 

P.33A-5

.

Q: Is the camber or caster out of specification?

YES : Adjust it. Then go to Step 10.
NO :  Go to Step 8.

ACX01131

WHILE ENGINE
RUNNING

WHILE ENGINE
STOPPED

AB

FLUID FLUCTUATION

POWER STEERING DIAGNOSIS

TSB Revision

POWER STEERING

37A-6

STEP 8. Check for excessive tie rod end ball joint 
breakaway torque.

Refer to 

P.37A-15

.

Q: Is there fault?

YES : Replace the part. Then go to Step 10.
NO :  Go to Step 9.

STEP 9. Check the gear box rack piston seal for damage.
Q: Is there damage?

YES : Replace it. Then go to Step 10.
NO :  There is no action to be taken.

STEP 10. Check steering wheel operation.

Verify that steering wheel operation is not difficult.
Q: Is the steering wheel operation difficult?

YES : Repeat from Step 1.
NO :  The procedure is complete.

INSPECTION PROCEDURE 3: Rattling Noise

.

DIAGNOSIS

STEP 1. Check for proper oil pump and gear box 
installation.

Q: Is the oil pump and gear box installation correct?

YES : 

Go to Step 2.

NO : 

Repair it. Then go to Step 4.

STEP 2. Check for interference of other parts with 
the steering column and power steering hoses.

Q: Is there interference?

YES : 

Correct the interference. Then go to Step 4.

NO : 

Go to Step 3.

STEP 3. Check for noise from inside the oil pump 
or gear box.

Q: Is there noise?

YES : 

Replace the part. Then go to Step 4.

NO : 

There is no action to be taken.

STEP 4. Check for rattling noise.

Confirm that no noise is generated.

Q: Is there noise?

YES : 

Repeat from Step 1.

NO : 

The procedure is complete.

INSPECTION PROCEDURE 4: Shrill Noise

.

DIAGNOSIS

STEP 1. Check for entry of air.

Q: Is the power steering fluid foamy?

YES : 

Bleed the air. Refer to 

P.37A-18

. Then go to 

Step 3.

NO : 

Go to Step 2.

STEP 2. Check for seizure in the oil pump.

Q: Is there seizure?

YES : 

Replace the part. Then go to Step 3.

NO : 

There is no action to be taken.

POWER STEERING DIAGNOSIS

TSB Revision

POWER STEERING

37A-7

STEP 3. Retest the system.

Confirm that no noise is generated.

Q: Is there noise?

YES : 

Repeat from Step 1.

NO : 

The procedure is complete.

INSPECTION PROCEDURE 5: Squealing Noise

.

DIAGNOSIS

STEP 1. Check the power steering belt tension.

CAUTION

Perform the check after rotating the engine in the normal 
direction (one revolution or more).
NOTE: Since the auto-tensioner is used, it is not necessary to 
adjust the tension of the belt.
(1) Check that the indicator mark of the auto-tensioner is 

located between the marks shown as "A" on the tensioner 
bracket.

(2) If the mark is located out of the space "A," replace the drive 

belt.

Q: Is the indicator mark of the auto-tensioner located 

between the marks shown as "A" on the tensioner 
bracket?
YES : Go to Step 2.
NO :  Replace the drive belt or auto-tensioner. Then go to 

Step 3.

STEP 2. Check for seizure in the oil pump.
Q: Is there seizure?

YES : Replace the part. Then go to Step 3.
NO :  There is no action to be taken.

STEP 3. Retest the system.

Confirm that no noise is generated.
Q: Is there noise?

YES : Repeat from Step 1.
NO :  The procedure is complete.

ACX00751AB

INDICATOR MARK

A

POWER STEERING DIAGNOSIS

TSB Revision

POWER STEERING

37A-8

INSPECTION PROCEDURE 6: Hissing Noise

.

DIAGNOSIS

STEP 1. Check for entry of air.

Q: Is the power steering fluid foamy?

YES : 

Bleed the air. Refer to 

P.37A-18

. Then go to 

Step 4.

NO : 

Go to Step 2.

STEP 2. Check each hose for crushing or 
twisting.

Q: Is any hose crushed or twisted?

YES : 

Repair or replace the hose. Then go to Step 

4.

NO : 

Go to Step 3.

STEP 3. Check the steering box for damage.

Q: Is there damage?

YES : 

Repair or replace the part. Then go to Step 

4.

NO : 

There is no action to be taken.

STEP 4. Retest the system.

Confirm that no noise is generated.

Q: Is there noise?

YES : 

Repeat from Step 1.

NO : 

The procedure is complete.

INSPECTION PROCEDURE 7: Droning Noise

.

DIAGNOSIS

STEP 1. Check the oil pump or oil pump bracket 
installation.

Q: Is the oil pump or oil pump bracket installation 

correct?

YES : 

Go to Step 2.

NO : 

Repair it. Then go to Step 3.

STEP 2. Check the oil pump for damage.
NOTE: If a slight "beat noise" is produced by the oil 
pump when the steering wheel is turned fully and 
held in that position, this is not a malfunction.

Q: Is there damage?

YES : 

Replace the oil pump. Then go to Step 3.

NO : 

There is no action to be taken.

STEP 3. Retest the system.

Confirm that no noise is generated.

Q: Is there noise?

YES : 

Repeat from Step 1.

NO : 

The procedure is complete.