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