engine ISUZU TF SERIES 2004 Workshop Manual

1-26 HEATER AND AIR CONDITIONING
ON-VEHICLE SERVICE

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 goggle 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) Using the ACR
4 (HFC-134a Refrigerant Recovery/
Recycling/Recharging/System) or equivalent to
thoroughly discharge and recover the refrigerant.
ACR
4 (115V 60Hz) : 5-8840-0629-0 (J-39500-A)
ACR4 (220-240V 50/60Hz)
: 5-8840-0630-0 (J-39500-220A)
ACR
4 (220-240V 50/60Hz Australian model)
: 5-8840-0631-0 (J-39500-220ANZ)
2) Remove and replace the defective part.
3)
After evacuation, charge the air conditioning system and
check for leaks.

HEATER AND AIR CONDITIONING 1-33
refrigerant container.


1) Make sure the evacuation process is correctly completed.
2) Connect the center-hose of the manifold gauge to the
refrigerant container.






Turn the charge valve handle counterclockwise to purge
to the charging line and purge any air exiting in the
center-hose of the manifold gauge.
3) Open the low-pressure hand valve and charge the
refrigerant about 200 g (0.44 lbs.).






Make sure the high-pressure hand valve is closed.






Avoid charging the refrigerant by turning the refrigerant
container upside down.
4) Close the low-pressure hand valve of the manifold gauge.






Check to ensure that the degree of pressure does not
change.
5) Check the refrigerant leaks by using a HFC-134a leak
detector.






If a leak occurs, repair the leak connection, and start all
over again from the first step of evacuation.
6) If no leaks are found, open the low-pressure hand valve of
the manifold gauge. Then continue charging refrigerant to
the system.






When charging the system becomes difficult:
(1) Run the engine at Idling and close the all vehicle
doors.
(2) A/C switch is "ON".
(3) Set the fan control knob (fan switch) to its highest
position.
(4) Set air soure selector lever to “RECIRC”



WARNING
BE ABSOLUTELY SURE NOT TO OPEN THE HIGH-
PRESSURE HAND VALVE. SHOULD THE HIGH-
PRESSURE HAND VALVE BE OPENED, THE HIGH-
PRESSURE REFRIGERANT GAS WOULD FLOW
BACKWARD, AND THIS MAY CAUSE THE REFRIGERANT
CONTAINER TO BURST.
7) When the refrigerant container is emptied, use the following
procedure to replace it with a new refrigerant container.
(1) Close the low-pressure hand valve.
(2) Raise the needle upward and remove the charge valve.
(3) Reinstall the charge valve to the new refrigerant
container.
(4) Purge any air existing in the center hose of the manifold
gauge.
8) Charge the system to the specified amount and then close
the low-pressure hand valve.
Refrigerant Amount g(lbs.)
720 (1.59)

1-34 HEATER AND AIR CONDITIONING


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

A fully charged system is indicated by the sight glass on
the receiver/drier being free of any bubbles (Refer to
"Reading Sight Glass").

Check the high and low pressure value of the manifold
gauge. (Refer to “CHECKING REFRIGERANT SYSTEM
WITH MAINFOLD GAUGE” in SERVICE
INFORMATION.)
Immediately after charging refrigerant, both high and low
pressures are slightly high and to the left of the gauge, but they
settle down to the guide pressure valves as shown below:
 Ambient temperature; 3035C (8695F)

Guide pressure
High-pressure side;
Approx. 1373
1670 kPa (14
17 kg/cm
2 / 199
242 PSI)
Low-pressure side;
Approx. 127
245 kPa (1.3
2.5 kg/cm
2 / 18
36 PSI)
10) Close the low pressure hand valve and charge valve of the
refrigerant container.
11) Stop the air conditioning and the engine.
12) Disconnect the high and low pressure hoses from the
manifold gauge fittings.

HEATER AND AIR CONDITIONING 1-35
Reading Sight Glass

High and low
pressure pipe
temperature The high pressure
pipe is hot and the
low pressure pipe
is cold. There is a
distinct difference
in temperature
between them. The high pressure
pipe is warm and
the low pressure
pipe is cool. There
is no great
difference in
temperature
between them. There is little
difference in
temperature
between the high
pressure pipe and
the low pressure
pipe. The high pressure
pipe is hot and the
low pressure pipe
is slightly warm.
There is a
difference in
temperature
between them.
Sight glass
condition Almost transparent.
A flow of bubbles
can be seen, but
they disappear
when the throttle is
opened.

A flow of bubbles
always can be
seen. It appears
sometimes
transparent, and
sometimes frothy.
Something like fog
faintly can be seen.
Evan at idle with
the fan at "HI" (with
the window fully
open), the bubbles
cannot be seen.



Air conditioning
cycle condition
OK NG
(Not enough
refrigerant) NG
(Almost no
refrigerant) NG
(Too much
refrigerant)

The sight glass provides accurate diagnosis only under the following conditions.
If the vehicle can be tested under these conditions, check the sight glass appearance and compare to the chart.
* Engine speed Idling
* A/C switch "ON"
* Blower fan operating at highest speed
* Air source selector lever at "RECIRC"
* Temperature control knob at coldest position
* Ambient temperature below 35
C (95
F) and humidity below 70% (See NOTE 1)
* High side pressure less than 1470 kPa (15 kg/cm
2 / 213 PSI) (See NOTE 2)

NOTE 1
If the vehicle cannot be moved to a testing location that meets these specifications, then the sight glass cannot be
used for diagnosis. You must discharge and recover the refrigerant, then recharge the system with the specified
amount of refrigerant. Then continue checking the system performance.

NOTE 2
If the high side pressure is greater than stated, the sight glass cannot be used for diagnosis. You must discharge
and recover the refrigerant, then recharge the system with the specified amount of refrigerant. Then continue
checking system performance.

1-36 HEATER AND AIR CONDITIONING
CONDENSER
REMOVAL AND INSTALLATION (4JA1-TC, 4JH1-TC)

This illustration is based on RHD model RTW410LF000501
Removal Steps
1. Radiator grille
2. Front bumper fascia

Refer to SECTION 2A “FRONT
BUMPER”
3. Front bumper inpact support assembly

Refer to SECTION 2A “FRONT
BUMPER”
4. Air cleaner assembly
5. Inter cooler

Refer to SECTION 6A “INTER COOLER”
6. Engine hood lock
7. Engine hood front end stay
8. Pressure switch connector
9. Condenser fan connector
10. Refrigerant line
11. Refrigerant line
12. Receiver/drier bracket
13. Receiver/drier
14. Condenser assembly
Installation Steps
14. Condenser assembly
13. Receiver/drier
12. Receiver/drier bracket
11. Refrigerant line
10. Refrigerant line
9. Condenser fan connector
8. Pressure switch connector
7. Engine hood front end stay
6. Engine hood lock
5. Inter cooler

Refer to SECTION 6A “INTER COOLER”
4. Air cleaner assembly
3. Front bumper inpact support assembly

Refer to SECTION 2A “FRONT
BUMPER”
2. Front bumper fascia

Refer to SECTION 2A “FRONT
BUMPER”
1. Radiator grille

HEATER AND AIR CONDITIONING 1-37

REMOVAL AND INSTALLATION (EXCEPT 4JA1-TC, 4JH1-TC)



RTW410LF000701

Removal Steps
1. Radiator grille
2. Engine hood lock
3. Engine hood front end stay
4. Pressure switch connector
5. Condenser fan connector
6. Refrigerant line
7. Refrigerant line
8. Receiver/drier bracket
9. Receiver/drier
10. Condenser assembly

Installation Steps
10. Condenser assembly
9. Receiver/drier
8. Receiver/drier bracket
7. Refrigerant line
6. Refrigerant line
5. Condenser fan connector
4. Pressure switch connector
3. Engine hood front end stay
2. Engine hood lock
1. Radiator grille

1-40 HEATER AND AIR CONDITIONING
COMPRESSOR
REMOVAL AND INSTALLATION (4J ENGINE)





852R300006
Removal Steps
1. Air duct
2. Magnetic clutch harness connector
3. Lock nut
4. Tension adjustment bolt
5. Drive belt
6. Refrigerant line
7. Bolt; compressor to bracket
8. Compressor assembly

Installation Steps
8. Compressor assembly

7. Bolt; compressor to bracket

6. Refrigerant line
5. Drive belt
4. Tension adjustment bolt
3. Lock nut
2. Magnetic clutch harness connector
1. Air duct

1-48 HEATER AND AIR CONDITIONING

Checking and Adjusting for Compressor
Replacement
180 cm3 (5.0 lmp fl oz) of oil is charged in compressor (service
parts). So it is necessary to drain the proper amount of oil from
the new compressor.
1) Perform oil return operation.
2) Discharge refrigerant and remove the compressor.
3) Drain the compressor oil and measure the extracted oil.
4) Check the compressor oil for contamination.
5) Adjust oil level as required.

Amount of oil drained
From used compressor Draining amount of oil
From new compressor
less than
90 cm
3 (2.5 lmp fl oz) Some as drained
amount
more than
90 cm
3 (2.5 lmp fl oz) 90 cm
3 (2.5 lmp fl oz)

6) Evacuate, charge and perform oil return operation.
7) Check system operation.


CONTAMINATION OF COMPRESSOR OIL
Unlike engine oil, no cleaning agent is added to the
compressor oil. Even is the compressor runs for a long period
of time (approximately 1 season), the oil never becomes
contaminated as long as there is nothing wrong with the
compressor or its method of use.
Inspect the extracted oil for any of the following
conditions:
 The capacity of the oil has increased.
 The oil has changed color to red.

Foreign substances, metal powder, etc., are present in the
oil.
If any of these conditions exists, compressor oil is
contaminated. Whenever contaminated compressor oil is
discovered, the receiver/drier must be replaced.

HEATER AND AIR CONDITIONING 1-49

OIL RETURN OPERATION
There is close affinity between the oil and the refrigerant.
During normal operation, part of the oil recirculates with the
refrigerant in the system.
When checking the amount of oil in the system, or replacing
any component of the system, the compressor must be run in
advance for oil return operation. The procedure is as follows:
1) Open the all doors and engine hood.
2) Start the engine and A/C switch is "ON" and Set the fan
control knob at its highest position.
3) Run the compressor for more than 20 minutes between
800 and 1,000 rpm in order to operate the system.
4) Stop the engine.


REPLACEMENT OF COMPONENT PARTS
When replacing system component parts, supply the following
amount of oil to the component parts to be installed.

Component parts to be installed Amount of oil
Evaporator 50 cm3 (1.7 fl.oz.)
Condenser 30 cm3 (1.0 fl.oz.)
Receiver/drier 30 cm3 (1.0 fl.oz.)
Refrigerant line (One piece) 10 cm3 (0.3 fl.oz.)

Refrigeration oil must be replenished if more than two parts
are removed at the same time. After installing these
components, check compressor oil.

1-50 HEATER AND AIR CONDITIONING
DISASSEMBLY


This illustration is based on the 4J engine model
871R300002

Disassembly Steps

1. Drive plate bolt
2. Plain washer

3. Drive plate
4. Snap ring

5. Pulley assembly

6. Snap ring
7. Thermo sensor and lead wire connector
8. Field coil
9. Compressor

Important Operations - Dissassembly


1. Drive Plate Bolt
Using drive plate holder to prevent the drive plate from rotating, then remove the bolt.
Drive Plate Holder: 5-8840-4056-0 (J-37872)