Isuzu KB P190. Manual - part 21

1-50  HEATER AND AIR CONDITIONING 

 

Important Operations - Installation 

 
 

4.  Bolt; Compressor to Bracket 

N

⋅m (kgf⋅m/lb⋅ft)

 

Torque  

44 (4.5/33) 

 

 
 

3. Refrigerant Line 

N

⋅m (kgf⋅m/lb⋅in)

 

Torque 11

∼19 (1.1/95∼1.9/168) 

 

 
 

 

2. Drive Belt 

  Refer to SECTION 6A “V-BELT TENSION OF 

ALTERNATER”. 

HEATER AND AIR CONDITIONING  1-51 

 
 

 

GENERAL REPAIR PROCEDURE 

OIL SPECIFICATION 

•  The HFC-134a system requires a synthetic (PAG) 

compressor oil. 

•  Compressor (PAG) oil varies according to compressor 

model. Be sure to use oil specified for the model of 

compressor. 

Specified Compressor Oil 

 

DH-PR 

 

 
 

 

HANDLING OF OIL 

•  The oil should be free from moisture, dust, metal powder, 

etc. 

•  Do not mix with other oil. 
•  The water content in the oil increases when exposed to the 

air.  After use, seal oil from air immediately. 

•  The compressor oil must be stored in steel containers, not 

in plastic containers. 

 

COMPRESSOR OIL CHECK 

The Oil used to lubricate the compressor is circulating with the 
refrigerant. 
Whenever replacing any component of the system or a large 
amount of gas leakage occurs, add oil to maintain the original 
amount of. oil. 
 
Oil Capacity 
  Capacity total in 

system 

CR-14 180 

cm

3

 (5.07 lmp fl oz) 

Compressor 
(Service parts) 
charging amount 

 

CR-14 

 

180 cm

3

 (5.07 lmp fl oz) 

 
 

1-52  HEATER AND AIR CONDITIONING 

 

 

Checking and Adjusting for Used Compressor 

(1) Perform Oil return operation. 

 

(Refer to "Oil Return Operation" in this section.) 

(2) Discharge refrigerant and remove the compressor. 

 

 
 

(3) Drain the compressor oil and measure the extracted oil with 

a measuring cylinder. 

(4) Check the compressor oil for contamination. 

 

(Refer to "Contamination of Compressor Oil" in this 

section.) 

(5) Adjust oil level following the procedure below. 
 

Type 

Collected Amount 

Charging Amount 

 

more than 90 cm

3

 

(2.53 lmp fl oz) 

same as collected 

amount 

 

less than 90 cm

3

 

(2.53 lmp fl oz) 

90 cm

3

  

(2.53 lmp fl oz) 

CR-14 

 
(6) Install the compressor, then evacuate, charge and perform 

oil return operation. 

(7) Check system operation. 
 

 
 

 

When it is impossible to perform oil return operation, the 
compressor oil should be checked in the following order:
(1) Discharge refrigerant and remove the compressor. 

(2) Drain the compressor oil and measure the extracted oil with 

a measuring cylinder. 

(3) Check the oil for contamination. 

(4) If more than 90 cm

3

 (2.53 lmp fl oz) for CR-14 type is 

extracted from the compressor, supply same amount of oil 

to the compressor to be installed. 

 

If the amount of oil extracted is less than 90 cm

3

 (2.53 lmp 

fl oz) for CR-14 type recheck the compressor oil in the 

following order: 

(5) Supply 90 cm

3

 (2.53 lmp fl oz) for CR-14 type oil to the 

compressor and install it onto the vehicle. 

(6) Perform oil return operation. 

(7) Remove the compressor and recheck the amount of oil. 

(8) Adjust the compressor oil. 
 

HEATER AND AIR CONDITIONING  1-53 

 

 

Checking and Adjusting for Compressor 
Replacement 

180 cm

3

 (5.07 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

 (2.53 lmp fl oz) 

Some as drained  

amount 

more than 

90 cm

3

 (2.53 lmp fl oz) 

90 cm

3

 (2.53 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.