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Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 15

HEATING, VENTILATION AND AIR CONDITIONING (HVAC) 1A–31

Air Conditioning System

Individual Inspection

Triple Pressure Switch (V6, A/T)

1. Disconnect the connector and check for continuity

between pressure switch side connector terminals (1)
and (2).

2. Reconnect the connector to activate the A/C switch,

and check to see if there is continuity between the
chassis side connector terminals (3) and (4) and the
fan operates.

875RY00010

Condenser Fan

1. Disconnect the condenser fan connector.
2. Connect the battery positive terminal to the

condenser fan side connector terminal No.C-16-1
and negative to the No.C-16-2.

3. Check that condenser fan is rotating correctly.

875R200002

General Repair Procedure

Precautions For Replacement or Repair of
Air Conditioning Parts

There are certain procedures, practices and precautions
that should be followed when servicing air conditioning
systems:

Keep your work area clean.

Always wear safety goggles and protective gloves
when working on refrigerant systems.

Beware of the danger of carbon monoxide fumes
caused by running the engine.

Beware of discharged refrigerant in enclosed or
improperly ventilated garages.

Always disconnect the negative battery cable and
discharge and recover the refrigerant whenever
repairing the air conditioning system.

When discharging and recovering the refrigerant, do
not allow refrigerant to discharge too fast; it will draw
compressor oil out of the system.

Keep moisture and contaminants out of the system.
When disconnecting or removing any lines or parts,
use plugs or caps to close the fittings immediately.
Never remove the caps or plugs until the lines or parts
are reconnected or installed.

When disconnecting or reconnecting the lines, use
two wrenches to support the line fitting, to prevent
from twisting or other damage.

Always install new O-rings whenever a connection is
disassembled.

Before connecting any hoses or lines, apply new
specified compressor oil to the O-rings.

When removing and replacing any parts which
require discharging the refrigerant circuit, the
operations described in this section must be
performed in the following sequence:

1. Use the J-39500 (ACR

: HFC-134a Refrigerant

Recovery / Recycling / Recharging / System) or
equivalent to thoroughly discharge and recover the
refrigerant.

2. Remove and replace the defective part.
3. After evacuation, charge the air conditioning

system and check for leaks.

1A–32 HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

Repair Of Refrigerant Leaks

Refrigerant Line Connections
Install new O-rings, if required. When disconnecting or
connecting lines, use two wrenches to prevent the
connecting portion from twisting or becoming damaged.

852R200001

When connecting the refrigerant line at a block joint,
securely insert the projecting portion of the joint portion
into the connecting hole on the unit side and secure with a
bolt. Apply the specified compressor oil to the O-rings
prior to connecting.

CAUTION: Compressor (PAG) oil to be used varies
according to the compressor model. Be sure to apply
oil specified for the model of compressor.

850RW002

O-rings (2) must be fitted in the groove (1) of refrigerant
line.

850RW003

Insert the nut into the union.
First, tighten the nut by hand as much as possible, then
tighten the nut to the specified torque.

850RW004

HEATING, VENTILATION AND AIR CONDITIONING (HVAC) 1A–33

Leak Check

Inspection of refrigerant leak

Refrigerant leak may cause an adverse effect not only on
the performance and durability of each component of the
air–conditioner, but also on the global atmosphere.
Therefore, it is most important to repair refrigerant leak
when there is any leak found.

Inspection flow of refrigerant leak

Step

Action

Yes

1. Evacuate the refrigerant system.
2. Charge the refrigerant.

Is there any refrigerant leak?

Repair refrigerant

system.

Go to

Step 2

1. Operate the compressor for more than 5 minutes to raise the

pressure on the high pressure side.

Is there any refrigerant leak at high pressure components?

Repair refrigerant

system.

Compressor

operation to be

confirmed.

Inspection Steps

Check the components of air–conditioner to see if there
occurs any refrigerant leak along the flow of refrigerant.

NOTE:

To avoid refrigerant leak detection error, avoid
refrigerant vapor and cigarette smoke presence when
performing the inspection. Also, select a location that
is not susceptible to wind, in case refrigerant vapor is
found it will not be blown off.

Inspection should be conducted chiefly on the pipe
connections and sections where a marked oil
contamination is found. When refrigerant is leaking,
oil inside is also leaking at the same time.

It is possible to visually check the leak from inside the
cooling unit. Follow the method below when
performing the inspection. Remove the drain hose or
resistor of the cooling unit, and insert a leak detector
to see if there are signs of leakage.

High Pressure Side

1. Discharger section of compressor.
2. Inlet/outlet section of condenser.
3. Inlet/outlet section of receiver driver.
4. Inlet section of cooling unit.

Low Pressure Side

1. Outlet section of cooling unit.
2. Intake section of compressor.

Major Checking Points of Refrigerant Leak

Compressor

Pipe connection

Sealing section of shaft

Mating section or cylinder

Condenser

Pipe connection

Welds of condenser body

Receiver driver

Pipe connection

Attaching section of pressure switch

Section around the sight glass

Evaporator unit (cooling unit)

Pipe connections

Connections of expansion valve

Brazed sections of evaporator

NOTE:

The evaporator and expansion valve are contained in
the case. Remove the drain hose or the resistor of the
cooling unit and insert a leak detector when checking
for any leak.

Flexible hose

Pipe connection

Caulking section of the hose

Hose (cracks, pinholes, flaws)

Pipe

Pipe connection

Pipe (cracks, flaws)

Charge valve

NOTE:

The charge valve, which is used to connect the gauge
manifold, is normally provided with a resin cap. When
the valve inside gets deteriorated, refrigerant will leak
out.

Leak at Refrigerant Line Connections

1. Check the torque on the refrigerant line fitting and, if

too loose, tighten to the specified torque.

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

Do not over tighten.

2. Perform a leak test on the refrigerant line fitting.

1A–34 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.

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

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

5. Retighten the refrigerant line fitting to the specified

torque.

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.

Cap the open connections at once.

4. Connect the new hose assembly.

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

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.

Always wear safety goggles and protective gloves.

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

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.

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

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.

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

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

Keep HFC-134a containers stored below 40

(104

F).

WARNING:

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

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.

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

: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

(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.

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