Mitsubishi Montero (2004+). Manual — part 618

ON-VEHICLE SERVICE

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-115

11.Insert a thermistor-type thermometer into the air vent shown

in the figure, and measure the air temperature.

12.Note the discharge air temperature.

NOTE: If the clutch cycles, take the reading before the
clutch disengages.

Performance Temperature Chart <Front-A/C test>

Performance Temperature Chart <Rear-A/C test>

REFRIGERANT LEAK REPAIR

M1552001500330

LOST CHARGE

If the system has lost all charge due to a leak:
1. Evacuate the system (See procedure).
2. Charge the system with approximately 0.453 kg (1

pound) of refrigerant.

3. Check for leaks.
4. Discharge the system.
5. Repair leaks.

ACX01485 AB

THERMOMETER

AC002699AB

THERMOMETER

GARAGE AMBIENT
TEMPERATURE

°C (°F)

20 (68)

25 (77)

35 (95)

40 (104)

Discharge air
temperature

°C (°F)

3.5

− 5.5 (38 − 42) 3.5 − 5.5 (38 − 42) 4.5 − 6.5 (40 − 44) 5.5 − 7.5 (42 − 46)

Compressor high
pressure kPa (psi)

1,050

− 1,250 (152

− 181)

1,050

− 1,250 (152

− 181)

1,400

− 1,600 (203

− 232)

1,650

− 1,850 (239

− 268)

Compressor low
pressure kPa (psi)

120

− 140 (17 −

20)

120

− 140 (17 −

20)

130

− 150 (19 −

22)

160

− 180 (23 −

26)

GARAGE AMBIENT
TEMPERATURE

°C (°F)

20 (68)

25 (77)

35 (95)

40 (104)

Discharge air
temperature

°C (°F)

5.5

− 7.5 (42 − 46) 5.5 − 7.5 (42 − 46) 6.5 − 8.5 (44 − 47) 7.5 − 9.5 (46 − 49)

Compressor high
pressure kPa (psi)

1,150

− 1,350 (167

− 196)

1,150

− 1,350 (167

− 196)

1,500

− 1,700 (218

− 247)

1,750

− 1,950 (254

− 283)

Compressor low
pressure kPa (psi)

130

− 150 (19 −

22)

130

− 150 (19 −

22)

140

− 160 (20 −

23)

180

− 200 (26 −

29)

ON-VEHICLE SERVICE

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-116

CAUTION

Replacement filter-drier units must be sealed
while in storage. The drier used in these units will
saturate water quickly upon exposure to the
atmosphere. When installing a drier, have all
tools and supplies ready for quick assembly to
avoid keeping the system open any longer than
necessary.
6. Replace receiver drier.
7. Evacuate and charge system.

LOW CHARGE

If the system has not lost all of its refrigerant charge,
locate and repair all leaks. If it is necessary to
increase the system pressure to find the leak
(because of an especially low charge) add refriger-
ant. If it is possible to repair the leak without dis-
charging the refrigerant system, use the procedure
for correcting low refrigerant level.

HANDLING TUBING AND FITTINGS

Kinks in the refrigerant tubing or sharp bends in the
refrigerant hose lines will greatly reduce the capacity
of the entire system. High pressures are produced in
the system when it is operating. Extreme care must
be exercised to make sure that all connections are

pressure tight. Dirt and moisture can enter the sys-
tem when it is opened for repair or replacement of
lines or components. The following precautions must
be observed. The system must be completely dis-
charged before opening any fitting of connection in
the refrigeration system. Open fittings with caution
even after the system has been discharged. If any
pressure is noticed as a fitting is loosened, allow
trapped pressure to bleed off very slowly.
Never attempt to rebend formed lines to fit. Use the
correct line for the installation you are servicing. A
good rule for the flexible hose lines is keep the radius
of all bends at least 10 times the diameter of the
hose.
Sharper bends will reduce the flow of refrigerant. The
flexible hose lines should be routed so that they are
at least 80 mm (3.1 inches) from the exhaust mani-
fold. It is good practice to inspect all flexible hose
lines at least once a year to make sure they are in
good condition and properly routed.
On standard plumbing fittings with O-rings, these
O-rings are not reusable.

COMPRESSOR NOISE CHECK

M1552008700120

.

You must first know the conditions when the noise occurs.
These conditions are: weather, vehicle speed, in gear or neu-
tral, engine temperature or any other special conditions. Noises
that develop during A/C operation can often be misleading. For
example: what sounds like a failed front bearing or connecting
rod, may be caused by loose bolts, nuts, mounting brackets, or
a loose clutch assembly. Verify accessory drive belt tension
(power steering or generator). Improper accessory drive belt
tension can cause a misleading noise when the compressor is
engaged and little or no noise when the compressor is disen-
gaged. Drive belts are speed-sensitive. That is, at different
engine speeds, and depending upon belt tension, belts can
develop unusual noises that are often mistaken for mechanical
problems within the compressor.

.

ADJUSTMENT
1. Select a quiet area for testing. Duplicate conditions as much

as possible. Switch compressor on and off several times to
clearly identify compressor noise. To duplicate high ambient
conditions (high head pressure), restrict air flow through
condenser. Install manifold gauge set to make sure
discharge pressure doesn't exceed 2,070 kPa (300 psi).

ON-VEHICLE SERVICE

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-117

2. Tighten all compressor mounting bolts, clutch mounting bolt,

and compressor drive belt. Check to assure clutch coil is
tight (no rotation or wobble).

3. Check refrigerant hoses for rubbing or interference that can

cause unusual noises.

4. Check refrigerant charge. (Refer to

P.55A-113

.)

5. Recheck compressor noise as in Step 1.
6. If noise still exists, loosen compressor mounting bolts and re

torque. Repeat Step 1.

7. If noise continues, replace compressor and repeat Step 1.

POWER RELAY CHECK

M1552008800387

.

FRONT BLOWER RELAY
Follow the table below to check the front blower relay for conti-
nuity.

.

BATTERY VOLTAGE

TESTER
CONNECTION

SPECIFIED
CONDITION

Not applied

2

− 5

Open circuit

• Connect terminal 3

to the positive
battery terminal

• Connect terminal 1

to the negative
battery terminal

2

− 5

Less than 2 ohms

AC204714AB

FRONT BLOWER RELAY

ON-VEHICLE SERVICE

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-118

A/C COMPRESSOR CLUTCH RELAY, CONDENSER FAN
RELAY
Follow the table below to check the A/C compressor clutch
relay and condenser fan for continuity.

.

REAR BLOWER RELAY
Follow the table below to check the rear blower relay for conti-
nuity.

IDLE-UP OPERATION CHECK

M1552001600263

.

1. Before inspection and adjustment, set vehicle in the

following condition:

BATTERY VOLTAGE

TESTER
CONNECTION

SPECIFIED
CONDITION

Not applied

4

− 5

Open circuit

• Connect terminal 3 to the

positive battery terminal

• Connect terminal 1 to the

negative battery terminal

4

− 5

Less than 2
ohms

AC204715

3

1

4

5

AE

A/C
COMPRESSOR
CLUTCH RELAY

BATTERY

BATTERY VOLTAGE

TESTER
CONNECTION

SPECIFIED
CONDITION

Not applied

4

− 5

Open circuit

• Connect terminal 1

to the positive
battery terminal

• Connect terminal 3

to the negative
battery terminal

4

− 5

Less than 2 ohms

AC204714

REAR BLOWER RELAY

AC