Mitsubishi Galant. Manual — part 724

ON-VEHICLE SERVICE

TSB Revision

HEATING AND AIR CONDITIONING

55-22

When a compressor is installed at the factory, it contains 120

cm

3

(4.1 floz) of refrigerant oil. While the A/C system is in

operation, the oil is carried through the entire system by the
refrigerant. Some of this oil will be trapped and retained in
various parts of the system.
When the following system components are changed, it is
necessary to add oil to the system to replace the oil being
removed with the component.

Compressor oil: SUN PAG 56

Quantity:

••••

Evaporator: 60 cm

3

(2.0 floz)

••••

Condenser: 15 cm

3

(0.5 floz)

••••

Suction hose: 10 cm

3

(0.3 floz)

••••

Receiver: 10 cm

3

(0.3 floz)

PERFORMANCE TEST

M1552001400076

1. The vehicles to be tested should be in a place that is not in

direct sunlight.

2. Close the high and low-pressure valve of the gauge

manifold.

3. Connect the charging hose (blue) to the low-pressure valve

and connect the charging hose (red) to the high-pressure
valve of the gauge manifold.

4. Install the quick joint (for low-pressure) to the charging hose

(blue), and connect the quick joint (for high-pressure) to the
charging hose (red).

CAUTION

•

To connect the quick joint, press section A firmly
against the service valve until a click is heard.

•

When connecting, run your hand along the hose while
pressing to ensure that there are no bends in the hose.

5. Connect the quick joint (for low-pressure) to the low-

pressure service valve and connect the quick joint (for high-
pressure) to the high-pressure service valve.

NOTE: The high-pressure service valve is on A/C pipe and
the low-pressure service valve is on the suction hose.

6. Start the engine.

7. Set the A/C controls as follows:

•

A/C switch: A/C

−

ON position

•

Mode selection: FACE position

•

Temperature control: MAXIMUM COOLING position

•

Air selection: RECIRCULATION position

•

Blower switch:

8. Adjust engine speed to 1,500 r/min with A/C clutch engaged.

9. Engine should be warmed up with doors and windows

closed.

AC001388

LOW-PRESSURE
VALVE

HIGH-PRESSURE
VALVE

GAUGE MANIFOLD

CHARGING
HOSE (RED)

A

SLEEVE

CHARGING
HOSE (BLUE)

ADAPTOR
VALVE
(FOR
LOW-PRES-
SURE)

ADAPTOR
VALVE
(FOR HIGH-
PRESSURE)

LOW-
PRESSURE
SERVICE
VALVE

HIGH-
PRESSURE
SERVICE
VALVE

AB

ON-VEHICLE SERVICE

TSB Revision

HEATING AND AIR CONDITIONING

55-23

10.Insert a thermometer in the center air outlet and operate the

engine for 20 minutes.

11.Note the discharge air temperature.

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

Performance Temperature Chart

REFRIGERANT LEAK REPAIR PROCEDURE

M1552001500073

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.

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
refrigerant. If it is possible to repair the leak without
discharging 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
system when it is opened for repair or replacement of
lines or components. The following precautions must
be observed. The system must be completely
discharged 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 rebind 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
manifold. 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.

AC002942

THERMOMETER

GARAGE AMBIENT TEMPERATURE

°°°°

C (

°°°°

F)

20 (68)

25 (77)

35 (95)

40 (104)

Discharge air temperature

°

C (

°

F)

5.0

−

10.0

(42

−

50)

6.0

−

10.5

(43

−

51)

7.5

−

12.0

(46

−

54)

7.5

−

12.5

(46

−

55)

Compressor high pressure kPa (psi)

1,540

−

1,935
(224

−

281)

1,618

−

2,000
(235

−

290)

2,070

−

2,205
(301

−

320)

2,140

−

2,620
(311

−

380)

Compressor low pressure kPa (psi)

125

−

155

(18

−

23)

125

−

155

(18

−

23)

150

−

180

(22

−

26)

145

−

190

(21

−

28)

ON-VEHICLE SERVICE

TSB Revision

HEATING AND AIR CONDITIONING

55-24

COMPRESSOR NOISE CHECK

M1552008700078

You must first know the conditions when the noise
occurs. These conditions are: weather, vehicle
speed, in gear or neutral, 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
disengaged.
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 (300.2 psi).

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.55-21

.)

5. Recheck compressor noise as in Step 1.

6. If noise still exists, loosen compressor mounting

bolts and retorque. Repeat Step 1.

7. If noise continues, replace compressor and repeat

Step 1.

POWER RELAY CHECK

M1552008800075

BLOWER RELAY

BATTERY
VOLTAGE

TERMINAL NO.
TO BE
CONNECTED TO
BATTERY

TERMINAL NO.
TO BE
CONDUCTED

SUPPLIED

1-3

2-5

NOT SUPPLIED

-

1-3

AC003706 AB

BLOWER RELAY

ON-VEHICLE SERVICE

TSB Revision

HEATING AND AIR CONDITIONING

55-25

A/C COMPRESSOR RELAY

FAN CONTROL RELAY CONTINUITY CHECK

IDLE-UP OPERATION CHECK

M1552001600070

1. Before inspection and adjustment, set vehicle in the

following condition:

•

Engine coolant temperature: 80

−

90

°

C (176.0 - 194.0

°

F

)

BATTERY
VOLTAGE

TERMINAL NO.
TO BE
CONNECTED TO
BATTERY

TERMINAL NO.
TO BE
CONDUCTED

SUPPLIED

1-3

4-5

NOT SUPPLIED

-

1-3

AC001391

A/C COMPRESSOR RELAY

AB

BATTERY
VOLTAGE

TERMINAL NO.
TO BE
CONNECTED TO
BATTERY

TERMINAL NO.
TO BE
CONDUCTED

SUPPLIED

1-3

2-5

NOT SUPPLIED

-

1-3

AC001392AB

FAN CONTROL RELAY