Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 1083

1A–54 HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

3. If the leak is still present, discharge and recover the

refrigerant from the system.

4. Replace the O-rings.

D

O-rings cannot be reused. Always replace with new
ones.

D

Be sure to apply the specified compressor oil to the
new O-rings.

5. Retighten the refrigerant line fitting to the specified

torque.

D

Use two wrenches to prevent twisting and damage
to the line.

6. Evacuate, charge and retest the system.

Leaks In The Hose

If the compressor inlet or outlet hose is leaking, the entire
hose must be replaced. The refrigerant hose must not be
cut or spliced for repair.

1. Locate the leak.
2. Discharge and recover the refrigerant.
3. Remove the hose assembly.

D

Cap the open connections at once.

4. Connect the new hose assembly.

D

Use two wrenches to prevent twisting or damage to
the hose fitting.

D

Tighten the hose fitting to the specified torque.

5. Evacuate, charge and test the system.

Compressor Leaks

If leaks are located around the compressor shaft seal or
shell, replace or repair the compressor.

Recovery, Recycling, Evacuation and
Charging of HFC-134a

Air conditioning systems contain HFC-134a. This is a
chemical mixture which requires special handling
procedures to avoid personal injury.

D

Always wear safety goggles and protective gloves.

D

Always work in a well-ventilated area. Do not weld or
steam clean on or near any vehicle-installed air
conditioning lines or components.

D

If HFC-134a should come in contact with any part of
the body, flush the exposed area with cold water and
immediately seek medical help.

D

If it is necessary to transport or carry any container of
HFC-134a in a vehicle, do not carry it in the
passenger compartment.

D

If it is necessary to fill a small HFC-134a container
from a large one, never fill the container completely.
Space should always be allowed above the liquid for
expansion.

D

HFC-134a and R-12 should never be mixed as their
compositions are not the same.

D

HFC-134a PAG oil tends to absorb moisture more
quickly than R-12 mineral oil and, therefore, should
be handled more carefully.

D

Keep HFC-134a containers stored below 40

°

C

(104

°

F).

WARNING:

D

SHOULD HFC-134A CONTACT YOUR EYE(S),
CONSULT A DOCTOR IMMEDIATELY.

D

DO NOT RUB THE AFFECTED EYE(S). INSTEAD,
SPLASH QUANTITIES OF FRESH COLD WATER
OVER THE AFFECTED AREA TO GRADUALLY
RAISE THE TEMPERATURE OF THE
REFRIGERANT ABOVE THE FREEZING POINT.

D

OBTAIN PROPER MEDICAL TREATMENT AS
SOON AS POSSIBLE. SHOULD THE HFC-134A
TOUCH THE SKIN, THE INJURY MUST BE
TREATED THE SAME AS SKIN WHICH HAS BEEN
FROSTBITTEN OR FROZEN.

Refrigerant Recovery

The refrigerant must be discharged and recovered by
using the J-39500 (ACR

4

:HFC-134a Refrigerant

Recovery/Recycling/Recharging/System) or equivalent
before removing or mounting air conditioning parts.

1. Connect the high and low charging hoses of the

ACR

4

(or equivalent) as shown below.

901R100022

Legend

(1) Low Side
(2) High Side

2. Recover the refrigerant by following the

Manufacturer’s Instructions.

3. When a part is removed, put a cap or a plug on the

connecting portion so that dust, dirt or moisture
cannot get into it.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC) 1A–55

Refrigerant Recycling

Recycle the refrigerant recovered by J-39500
(ACR

4

:HFC-134a Refrigerant Recovery / Recycling /

Recharging / System) or equivalent.
For the details of the actual operation, follow the steps in
the ACR

4

(or equivalent) Manufacturer’s Instructions.

Evacuation of The Refrigerant System

901R100023

Legend

(1) Low Side
(2) High Side

NOTE: Explained below is a method using a vacuum
pump. Refer to the ACR

4

(or equivalent) manufacturer’s

instructions when evacuating the system with a ACR

4

(or

equivalent).

Air and moisture in the refrigerant will cause problems in
the air conditioning system. Therefore, before charging
the refrigerant, be sure to evacuate air and moisture thor-
oughly from the system.

1. Connect the gauge manifold.

D

High-pressure valve (HI) — Discharge-side.

D

Low-pressure valve (LOW) — Suction-side.

2. Discharge and recover the refrigerant.
3. Connect the center hose of the gauge manifold set to

the vacuum pump inlet.

4. Operate the vacuum pump, open shutoff valve and

then open both hand valves.

5. When the low-pressure gauge indicates

approximately 750 mmHg (30 inHg), continue the
evacuation for 5 minutes or more.

6. Close both hand valves and stop the vacuum pump.
7. Check to ensure that the pressure does not change

after 10 minutes or more.

D

If the pressure changes, check the system for
leaks.

D

If leaks occur, retighten the refrigerant line
connections and repeat the evacuation steps.

8. If no leaks are found, again operate the vacuum pump

for 20 minutes or more.  After confirming that the
gauge manifold pressure is at 750 mmHg (30 inHg),
close both hand valves.

9. Close positive shutoff valve. Stop the vacuum pump

and disconnect the center hose from the vacuum
pump.

Charging The Refrigerant System

There are various methods of charging refrigerant into the
air conditioning system.
These include using J-39500 (ACR

4

:HFC-134a

Refrigerant Recovery/Recycling/Recharging/System) or
equivalent and direct charging with a weight scale
charging station.

Charging Procedure

D

ACR

4

(or equivalent) Method

For the charging of refrigerant recovered by ACR

4

(or

equivalent), follow the manufacturer’s instruction.

901R100022

Legend

(1) Low Side
(2) High Side

D

Direct charging with a weight scale charging
station method

1. Make sure the evacuation process is correctly

completed.

2. Connect the center hose of the manifold gauge to the

weight scale.

1A–56 HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

3. Connect the low pressure charging hose of the

manifold gauge to the low pressure side service valve
of the vehicle.

4. Connect the high pressure charging hose of the

manifold gauge to the high pressure side service
valve of the vehicle.

901R100021

Legend

(1) Low Side
(2) High Side
(3) Refrigerant Container
(4) Weight Scale

5. Place the refrigerant container(3) up right on a weight

scale(4).
Note the total weight before charging the refrigerant.

a. Open the refrigerant container valve.
b. Open the low side vale on the manifold gauge set.

Refer to the manufacturer’s instructions for a
weight scale charging station.

901RS144

6. Perform a system leak test:

D

Charge the system with approximately 200 g
(0.44 lbs) of HFC-134a.

D

Make sure the high pressure valve of the manifold
gauge is closed.

D

Check to ensure that the degree of pressure does
not change.

D

Check for refrigerant leaks by using a HFC-134a
leak detector.

D

If a leak occurs, recover the refrigerant. Repair the
leak and start all over again from the first step of
evacuation.

7. If no leaks are found, continue charging refrigerant to

the air conditioning system.

D

Charge the refrigerant until the scale reading
decreases by the amount of the charge specified.

Specified amount: 650 g (1.43 lbs)

D

If charging the system becomes difficult:

1. Run the engine at idle and close all the vehicle

doors.

2. Turn A/C switch “ON”.
3. Set the fan switch to its highest position.
4. Set the air source selector lever to “CIRC”.
5. Slowly open the low side valve on the manifold

gauge set.

WARNING: BE ABSOLUTELY SURE NOT TO OPEN
THE HIGH PRESSURE VALVE OF THE MANIFOLD
GAUGE. SHOULD THE HIGH PRESSURE VALVE BE
OPENED, THE HIGH PRESSURE REFRIGERANT
WOULD FLOW BACKWARD, AND THIS MAY CAUSE
THE REFRIGERANT CONTAINER TO BURST.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC) 1A–57

8. When finished with the refrigerant charging, close the

low pressure valve of the manifold gauge and
container valve.

9. Check for refrigerant leaks.

Checking The A/C System

1. Run the engine and close all the vehicle doors.
2. Turn A/C switch “ON”, set the fan switch to its highest

position.

3. Set the air source lever to “CIRC”, set the

temperature lever to the full cool position.

4. Check the high and low pressure of the manifold

gauge.

D

Immediately after charging refrigerant, both high
and low pressures might be slightly high, but they
settle down to the pressure guidelines shown
below:

D

The ambient temperature should be between
25–30

°

C (77–86

°

F).

D

The pressure guideline for the high-pressure side is
approximately 1372.9–1863.3 kPa (199.1–270.2
psi).

D

The pressure guideline for the low-pressure side is
approximately 147.1–294.2 kPa (21.3–42.7  psi).

D

If an abnormal pressure is found, refer to Checking
The Refrigerant System With Manifold Gauge in
this section.

5. Put your hand in front of the air outlet and move the

temperature control lever of the control panel to
different positions.  Check if the outlet temperature
changes as selected by the control knob.