Mitsubishi Evolution X. Manual — part 1291

ON-VEHICLE SERVICE

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55-115

PERFORMANCE TEST

M1552001400957

The vehicles to be tested should be parked out of direct sun-
light.
1. Close the high and low-pressure valve of the gauge

manifold.

2. 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.

3. 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.

4. 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 the A/C pipe
and the low-pressure service valve is on the suction hose.

5. Start the engine.
6. 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: Maximum air volume

7. Set the engine speed to the idle speed.
8. Engine should be warmed up with hood, doors and windows

opened.

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

engine for 20 minutes.
NOTE: If the A/C clutch cycles, take the reading before the
clutch disengages.

10.Note the discharge air temperature.

AC609415

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

AC

AC609414AB

Thermometer

ON-VEHICLE SERVICE

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55-116

PERFORMANCE TEMPERATURE CHART

REFRIGERANT LEAK REPAIR PROCEDURE

M1552001500448

LOST CHARGE

If the system has lost all charge due to a leak:
1. Evacuate the system. (Refer to

P.55-114

).

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 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.

Garage
ambient air
temperature
° C (° F)

20 (68)

25 (77)

30 (86)

35 (95)

40 (104)

45 (113)

50 (122)

Discharge air
temperature
° C (° F)

4.7 (40)

−

17 (63)

10 (50)

− 23

(73)

15 (59)

− 28

(82)

20 (68)

− 33

(91)

26 (79)

− 38

(100)

31 (88)

− 44

(111)

36 (97)

− 49

(120)

Compressor
high pressure
kPa (psi)

934 (136)

−

1700 (247)

1068 (155)
− 1850

(268)

1201 (174)
− 2000

(290)

1335 (193)
− 2150

(312)

1468 (213)
− 2300

(334)

1602 (232)
− 2450

(355)

1735 (252)
− 2600

(377)

Compressor
low pressure
kPa (psi)

170 (24.7)

−

359 (52.1)

215 (31.2)

−

406 (58.9)

260 (37.7)

−

452 (65.6)

305 (44.2)

−

499 (72.4)

350 (50.8)

−

545 (79.1)

395 (57.3)

−

592 (85.9)

440 (63.8)

−

638 (92.6)

ON-VEHICLE SERVICE

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55-117

COMPRESSOR NOISE CHECK

M1552008700487

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 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 mis-
taken for mechanical problems within the compres-
sor.

ADJUSTMENT

1. Select a quiet area for testing. Duplicate

conditions as much as possible. Switch the
compressor on and off several times to clearly
identify compressor noise. To duplicate high
ambient conditions (high head pressure), restrict
air flow through the condenser. Install a 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.55-114

).

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

bolts and retighten. Repeat Step 1.

7. If noise continues, replace compressor and repeat

from Step 1.

POWER RELAY CHECK

M1552008800967

A/C COMPRESSOR CLUTCH RELAY CONTINUITY
CHECK

Battery voltage

Tester connection Specified

condition

Not applied

3

− 4

Open circuit

• Connect

terminal 2 to the
positive battery
terminal

• Connect

terminal 1 to the
negative battery
terminal

3

− 4

Less than 2 ohms

AC605626

AC609971

AB

4

1

2

3

3

1

4

2

A/C compressor clutch relay

ON-VEHICLE SERVICE

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55-118

BLOWER RELAY CONTINUITY CHECK

IDLE-UP OPERATION CHECK

M1552001601169

Before inspection and adjustment, set vehicle in the following

condition:

• Engine coolant temperature: 80 − 90 ° C (176.0 − 194.0 ° F)

• Lights, electric cooling fan and accessories: OFF

• Transmission: Neutral ("N" or "P" position)

• Steering wheel: Straightforward

1. Check whether or not the idle speed is the standard value.

Refer to GROUP 11A, On-vehicle Service

− Idle Speed

Check

P.11A-12

.

Standard value: 700

± 50 r/min

2. Turn on the air conditioning switch and the blower speed

selection dial. Engine idling speed should be within the
standard value:

Standard value: 800

± 50 r/min

NOTE: It is not necessary to make an adjustment, because
the idling speed is automatically adjusted by the ISC sys-
tem. If, however, a deviation from the standard value occurs
for some reason, check the ISC system (Refer to GROUP
11A, On-vehicle Service

−

Idle Speed Check

P.11A-12

)

Battery voltage

Tester connection Specified

condition

Not applied

3

− 4

Open circuit

• Connect

terminal 1 to the
positive battery
terminal

• Connect

terminal 2 to the
negative battery
terminal

3

− 4

Less than 2 ohms

AC605627

AC609984

AB

Blower relay

4

1

2

3

4

1

3

2