Mitsubishi Montero (2004+). Manual — part 1146

ENGINE COOLING DIAGNOSIS

TSB Revision

ENGINE COOLING

14-3

SYMPTOM PROCEDURES

INSPECTION PROCEDURE 1: Coolant Leak

DIAGNOSIS

STEP 1. Check for coolant leaks.

WARNING

When pressure testing the cooling system, slowly
release cooling system pressure to avoid getting
burned by hot coolant.

CAUTION

• Be sure to completely clean away any moisture from

the places checked.

• When the tester is removed, be careful not to spill any

coolant.

• When installing and removing the tester and when test-

ing, be careful not to deform the filler neck of the radia-
tor.

Check that the coolant level is up to the filler neck. Install a radi-
ator tester and apply 160 kPa (23 psi) pressure, and then check
for leakage from the radiator hose or connections.
Q: Is leakage present from the radiator hose or

connections?
YES : Repair or replace the appropriate part, then go to

Step 2.

NO : There is no action to be taken.

STEP 2. Retest the system.
Q: It there still coolant leakage?

YES : Return to Step 1.
NO : The procedure is complete.

INSPECTION PROCEDURE 2: Engine Overheating

DIAGNOSIS

STEP 1. Remove the radiator cap and check for coolant
contamination.
Q: Is the coolant contaminated with rust and oil?

YES : Replace it. Refer to

P.14-6

.

NO : There is no action to be taken. Go to Step 2.

ACX01844 AB

CAP ADAPTER

ADAPTER

ENGINE COOLING DIAGNOSIS

TSB Revision

ENGINE COOLING

14-4

STEP 2. Check the radiator cap valve opening pressure.
NOTE: Be sure that the cap is clean before testing. Rust or
other foreign material on the cap seal will cause an improper
reading.
(1) Use a cap adapter to attach the cap to the tester.
(2) Increase the pressure until the gauge indicator stops

moving.

Minimum limit: 83 kPa (12 psi)
Standard value: 93

− 123 kPa (14 − 18 psi)

Q: Does the reading remain at or above the minimum limit?

YES : Go to Step 3.
NO : Replace the radiator cap. Then go to Step 5.

STEP 3. Check thermostat operation.

Refer to

P.14-14

.

Q: Does the thermostat operate correctly?

YES : Go to Step 4.
NO : Replace the thermostat, then go to Step 5.

STEP 4. Check the drive belt for slippage or damage.

Refer to GROUP 00, Maintenance Service

− Drive Belts

(Check Condition)

P.00-41

.

Q: Is the drive belt loose or damaged?

YES : Adjust or replace the drive belt, then go to Step 5.
NO : There is no action to be taken.

STEP 5. Retest the system.

Check the coolant temperature gauge.
Q: Is the coolant temperature abnormally high?

YES : Return to Step 2.
NO : The procedure is complete.

ACX01845 AB

CAP ADAPTER

ON-VEHICLE SERVICE

TSB Revision

ENGINE COOLING

14-5

ON-VEHICLE SERVICE

ENGINE COOLANT LEAK CHECK

M1141001000247

WARNING

When pressure testing the cooling system, slowly
release cooling system pressure to avoid getting
burned by hot coolant.

CAUTION

• Be sure to completely clean away any moisture from

the places checked.

• When the tester is taken out, be careful not to spill any

coolant.

• Be careful when installing and removing the tester and

when testing not to deform the filler neck of the radia-
tor.

1. Check that the coolant level is up to the filler neck. Install a

radiator tester and apply 160 kPa (23 psi) pressure, and
then check for leakage from the radiator hose or
connections.

2. If there is leakage, repair or replace the appropriate part.

RADIATOR CAP PRESSURE CHECK

M1141001300293

NOTE: Be sure that the cap is clean before testing. Rust or
other foreign material on the cap seal will cause an improper
reading.
1. Use a cap adapter to attach the cap to the tester.
2. Increase the pressure until the indicator of the gauge stops

moving.

Minimum limit: 83 kPa (12 psi)
Standard value: 93

− 123 kPa (14 − 18 psi)

3. Replace the radiator cap if the reading does not remain at or

above the limit.

ACX01844 AB

CAP ADAPTER

ADAPTER

ACX01845 AB

CAP ADAPTER

ON-VEHICLE SERVICE

TSB Revision

ENGINE COOLING

14-6

ENGINE COOLANT REPLACEMENT

M1141001200326

Changing Coolant

1. Set the temperature control knob to the "HOT" position.

WARNING

When removing the radiator cap, use care to avoid
contact with hot coolant or steam. Place a shop towel
over the cap and turn the cap counterclockwise a lit-
tle to let the pressure escape through the vinyl tube.
After relieving the steam pressure, remove the cap by
slowly turning it counterclockwise.

2. Remove the radiator cap, radiator drain plug and engine

drain plug to drain the coolant.

3. Remove the reserve tank and drain the coolant.
4. Drain the cooling water then clean the path of the cooling

water by injecting water into the radiator from the radiator
cap area.

5. Apply the designated sealant to the screw area of the

cylinder block drain plug, and then tighten to the standard
torque.

Specified sealant: 3M

 Nut Locking Part number 4171

or equivalent
Tightening torque: 39

± 5 N⋅m (29 ± 3 ft-lb)

6. Securely tighten the drain plug of the radiator.
7. Assemble the reservoir tank.

CAUTION

Do not use alcohol or methanol anti-freeze or any engine
coolants mixed with alcohol or methanol anti-freeze. The
use of an improper anti-freeze can cause the corrosion of
the aluminum components.
8. <Refilling engine coolant without the special tool>

(1) Loosen the air bleed bolt.
(2) By referring to the section on coolant, select an

appropriate concentration for safe operating temperature
within the range of 30 to 60%. Refill the system with a
high quality ethylene glycol antifreeze at the selected
concentration. A convenient mixture is a 50% water and
50% antifreeze solution [freezing point:

−31°C (−32.8°F)].

Pour in coolant until it overflows from the air bleed bolt
hole, and then tighten the air bleed bolt.

AC200625AB

CYLINDER BLOCK
DRAIN PLUG

AC203797

AB

CAUTION LABEL

AIR BLEED BOLT

14±1 N·m
120±13 in-lb