Isuzu KB P190. Manual — part 22

1-54 HEATER AND AIR CONDITIONING

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

cm

3

(1.41 lmp fl oz)

Condenser 30

cm

3

(0.84 lmp fl oz)

Receiver/drier 30

cm

3

(0.84 lmp fl oz)

Refrigerant line (One piece)

10 cm

3

(0.28 lmp 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.

HEATER AND AIR CONDITIONING 1-55

DISASSEMBLY

This illustration is based on the 4J engine model

RTW510MF000301

Disassembly Steps

1. Drive plate bolt

2. Plain washer

3. Drive plate

4. Snap ring

5. Pulley assembly

6. Snap ring

7. Field coil

8.

Compressor

Important Operations - Disassembly

RTW510SH000701

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)

1-56 HEATER AND AIR CONDITIONING

3. Drive Plate

Remove the drive plate.

If the frictional surface shows signs of damage due to

excessive heat, the drive plate and pulley should be

replaced.

RTW510SH000801

5. Pulley Assembly

Using pulley puller pilot and pulley puller to remove the

pulley assembly.

Pulley Puller Pilot: 5-8840-0121-0 (J-33943)

Pulley Puller:

5-8840-0111-0 (J-8433)

Check the appearance of the pulley assembly. If the

frictional surface of the pulley shows signs of excessive

grooving due to slippage, both the pulley and drive plate

should be replaced. The frictional surfaces of the pulley

assembly should be cleaned with a suitable solvent before

reinstallation.

RTW510SH000901

6. Snap ring

Using snap ring pliers to remove the snap ring.

HEATER AND AIR CONDITIONING 1-57

REASSEMBLY

This illustration is based on the 4J engine model

RTW510MF000401

Reassembly Steps

1.

Compressor

2. Field coil

3. Snap ring

4. Pulley assembly

2. Snap ring
3. Drive plate
7. Plain washer

8. Drive prate bolt