Hummer H2. Manual - part 1970

The J 43600 is a complete air conditioning service center for R-134a. The ACR 2000 recovers, recycles, 
evacuates and recharges A/C refrigerant quickly, accurately and automatically. The unit has a display screen 
that contains the function controls and displays prompts that will lead the technician through the recover, 
recycle, evacuate and recharge operations. R-134a is recovered into and charged out of an internal storage 
vessel. The ACR 2000 automatically replenishes this vessel from an external source tank in order to maintain a 
constant 5.45-6.82 kg (12-15 lbs) of A/C refrigerant. See Special Tools and Equipment . 

The ACR 2000 has a built in A/C refrigerant identifier that will test for contamination, prior to recovery and 
will notify the technician if there are foreign gases present in the A/C system. If foreign gases are present, the 
ACR 2000 will not recover the refrigerant from the A/C system. 

The ACR 2000 also features automatic air purge, single pass recycling and an automatic oil drain.

or the mist. Exposure may irritate the eyes, nose, and throat. Work in a 
well ventilated area. In order to remove R-134a from the A/C system, use 
service equipment that is certified to meet the requirements of SAE J 2210 
(R-134a recycling equipment). If an accidental system discharge occurs, 
ventilate the work area before continuing service. Additional health and 
safety information may be obtained from the refrigerant and lubricant 
manufacturers.

CAUTION: For personal protection, goggles and gloves should be worn and a clean 

cloth wrapped around fittings, valves, and connections when doing work 
that includes opening the refrigerant system. If R-134a comes in contact 
with any part of the body severe frostbite and personal injury can result. 
The exposed area should be flushed immediately with cold water and 
prompt medical help should be obtained.

NOTE:

R-134a is the only approved refrigerant for use in this vehicle. The use of any 
other refrigerant may result in poor system performance or component failure.

NOTE:

To avoid system damage use only R-134a dedicated tools when servicing the 
A/C system.

NOTE:

Use only Polyalkylene Glycol Synthetic Refrigerant Oil (PAG) for internal 
circulation through the R-134a A/C system and only 525 viscosity mineral oil on 
fitting threads and O-rings. If lubricants other than those specified are used, 
compressor failure and/or fitting seizure may result.

NOTE:

R-12 refrigerant and R-134a refrigerant must never be mixed, even in the 
smallest of amounts, as they are incompatible with each other. If the 
refrigerants are mixed, compressor failure is likely to occur. Refer to the 
manufacturer instructions included with the service equipment before 
servicing.

 

2004 Hummer H2 

2004 HVAC Heating, Ventilation and Air Conditioning - Hummer H2

  

Refer to the J 43600 ACR 2000 manual for operation and setup instruction. Always recharge the A/C System 
with the proper amount of R-134a. Refer to Refrigerant System Capacities for the correct amount. See 
Special Tools and Equipment . 

A/C Refrigerant System Oil Charge Replenishing 

If oil was removed from the A/C system during the recovery process or due to component replacement, the oil 
must be replenished. Oil can be injected into a charged system using J 45037 . For the proper quantities of oil to 
add to the A/C refrigerant system, refer to Refrigerant System Capacities . See Special Tools and 
Equipment . 

FLUSHING 

Tools Required 

z

J 43600 ACR 2000 Air Conditioning Service Center. See Special Tools and Equipment .  

z

J 45268 Flush Adapter Kit. See Special Tools and Equipment .  

z

J 41447 Leak Detection Dye. See Special Tools and Equipment .  

z

J 42220 Universal 12V Leak Detection Lamp. See Special Tools and Equipment .  

Flushing is intended to remove the following: 

z

Contaminated PAG oil  

z

Desiccant, following a desiccant bag failure  

z

Overcharge of PAG oil  

z

Refrigerant contamination  

1. Recover the refrigerant. Refer to Refrigerant Recovery and Recharging .  

2. Remove the orifice tube. Refer to Expansion (Orifice) Tube Replacement .  

3. Connect the A/C lines with the orifice tube removed.  

4. Remove the A/C compressor. Refer to Compressor Replacement .  

5. Install J 45268-5 to the A/C discharge hose.  

6. Install J 45268-4 to the A/C suction hose. 

IMPORTANT: Flushing with the ACR 2000 is not intended to remove metal from the A/C 

system.

IMPORTANT: Warmer engine or ambient temperature decreases the refrigerant 

recovery time during the A/C flush procedure.

 

2004 Hummer H2 

2004 HVAC Heating, Ventilation and Air Conditioning - Hummer H2

  

Fig. 2: Removing Check Valve 
Courtesy of GENERAL MOTORS CORP. 

7. Forward flow refrigerant flushing is recommended for contaminated refrigerant or PAG oil. 

Perform the following procedure: 

1. Service the filter with ACDelco P/N GF 470, before each flush. 

Connect J 45268-1 flush filter to the suction port of J 45268 -4 flush adapter. See Special Tools 
and Equipment . 

2. Install the blue hose from J 43600 to J 45268-1 flush filter adapter. See Special Tools and 

Equipment .  

3. Install the red hose from J 43600 to J 45268-5. See Special Tools and Equipment .  

8. Reverse flow refrigerant flushing is recommended for desiccant bag failure only. 

Perform the following procedure and replace the accumulator when the flush is complete: 

1. Service the filter with ACDelco P/N GF 470, before each flush. 

Connect the J 45268-1 flush filter to the discharge port of the J 45268-5 flush adapter. 

2. Install the blue hose from J 43600 to J 45268-1 flush filter adapter. See Special Tools and 

IMPORTANT: The filter inside J 45268-1 is serviceable. Remove and discard the 

check valve from the filter.

IMPORTANT: The filter inside J 45268-1 is serviceable. Remove and discard the 

check valve from the filter.

 

2004 Hummer H2 

2004 HVAC Heating, Ventilation and Air Conditioning - Hummer H2

  

Equipment .  

3. Install the red hose from J 43600 to the suction port of J 45268-4. See Special Tools and 

Equipment .  

9. Flush the A/C system. Follow the instructions supplied with the J 43600 . See Special Tools and 

Equipment .  

10. Remove J 45268-4 from the A/C suction hose.  

11. Remove J 45268-5 from the A/C discharge hose. 

12. Drain the PAG oil from the A/C Compressor. Rotate the compressor input shaft to assist in draining the 

PAG oil from the compressor.  

13. Add back the total system capacity of PAG oil to the A/C compressor. Refer to Refrigerant System 

Capacities . 

14. Add one bottle of J 41447 directly to the A/C compressor. See Special Tools and Equipment .  

15. Install the A/C compressor. Refer to Compressor Replacement .  

16. Inspect the orifice tube for debris. Clean or replace as needed.  

17. Install the orifice tube. Refer to Expansion (Orifice) Tube Replacement .  

18. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging .  

19. Leak test the fittings using the J 42220 . See Special Tools and Equipment .  

COMPRESSOR OIL BALANCING 

Draining 

1. Drain the oil from both the suction and discharge ports of the removed compressor into a clean, graduated 

container. 

Rotate the compressor shaft to assist in draining the compressor.

IMPORTANT: Close the valve on the external refrigerant tank, before starting the flush 

process.

IMPORTANT: Flushing will remove all the PAG oil from the A/C system. 

The A/C system must be replenished with the correct amount of PAG oil.

IMPORTANT: Flushing will remove the fluorescent leak detection dye from the A/C 

system.

IMPORTANT: Drain and measure as much of the refrigerant oil as possible from the 

removed compressor.

 

2004 Hummer H2 

2004 HVAC Heating, Ventilation and Air Conditioning - Hummer H2