Mitsubishi Galant 9G. Manual — part 339

ENGINE COOLING DIAGNOSIS

TSB Revision

ENGINE COOLING

14-4

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.14-7

.

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

ACX01844 AB

CAP ADAPTER

ADAPTER

ENGINE COOLING DIAGNOSIS

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ENGINE COOLING

14-5

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.14-18

.

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). <2.4L Engine>

P.00-45

, <3.8L

Engine>

P.00-45

.

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 engine coolant temperature.
Q: Is the engine 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

14-6

ON-VEHICLE SERVICE

ENGINE COOLANT LEAK CHECK

M1141001000333

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

M1141001300419

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

14-7

ENGINE COOLANT REPLACEMENT

M1141001200478

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.

1. Drain the water from the radiator, heater core and engine

after unplugging the radiator drain plug and removing the
radiator cap.

2. Drain the water in the water jacket by unplugging the drain

plug of the cylinder block.

3. Remove the radiator condenser tank assembly and drain the

coolant.

4. Drain the coolant then clean the path of the coolant by

injecting water into the radiator from the radiator cap area.

AC304173AC

CYLINDER BLOCK
DRAIN PLUG

INTAKE MANIFOLD

<2.4L ENGINE>

AC306131AB

<3.8L ENGINE: LEFT BANK>

CYLINDER BLOCK
DRAIN PLUG

AC306132AB

<3.8L ENGINE: RIGHT BANK>

CYLINDER BLOCK
DRAIN PLUG