Hummer H2. Manual - part 1962

2004 HVAC

Heating, Ventilation and Air Conditioning - Hummer H2 

SPECIFICATIONS 

FASTENER TIGHTENING SPECIFICATIONS 

Fastener Tightening Specifications 

Application

Specification

Metric

English

A/C Accumulator Nut to Evaporator

16 N.m

12 lb ft

A/C Belt Tensioner Bolts

50 N.m

37 lb ft

A/C Low Pressure Switch

6 N.m

53 lb in

A/C Refrigerant Filter Retaining Nuts

15 N.m

11 lb ft

A/C Refrigerant Pressure Sensor

6 N.m

53 lb in

Accumulator Bracket Nut

9 N.m

80 lb in

Accumulator Clamp Bolt

10 N.m

8 lb ft

Air Distribution Duct Screws

2 N.m

18 lb in

Air Distribution Housing Screws

2 N.m

18 lb in

Blower Motor Screws

2 N.m

18 lb in

Compressor Bracket Mounting Bolts

50 N.m

37 lb ft

Compressor Clutch Plate Retaining Bolt

18 N.m

13 lb ft

Compressor Discharge Hose to Condenser Nut

16 N.m

12 lb ft

Compressor Mounting Bolts

50 N.m

37 lb ft

Compressor Suction/Discharge Hose Bolt

16 N.m

12 lb ft

Compressor Suction Hose at Accumulator Nut

16 N.m

12 lb ft

Condenser Upper Insulator Retainer Bolts

9 N.m

80 lb in

Evaporator Core Cover Screws

2 N.m

18 lb in

Evaporator Tube Fitting at Orifice

25 N.m

18 lb ft

Evaporator Tube at Condenser Nut

16 N.m

12 lb ft

Evaporator Tube at Evaporator Nut

16 N.m

12 lb ft

Filter Access Door Screw

2 N.m

18 lb in

Floor Air Outlet Duct Screw

1.6 N.m

14 lb in

Heater Core Cover Screws

2 N.m

18 lb in

Hood Spring Mounting Bolt and Nut

17 N.m

13 lb ft

HVAC Module Mounting Bolts

4 N.m

35 lb in

HVAC Module Mounting Nuts

9 N.m

80 lb in

HVAC Module Screws

2 N.m

18 lb in

Mode Actuator Screws

2 N.m

18 lb in

Recirculation Actuator Screws

17 N.m

13 lb ft

 

2004 Hummer H2 

2004 HVAC Heating, Ventilation and Air Conditioning - Hummer H2

  

 

2004 Hummer H2 

2004 HVAC Heating, Ventilation and Air Conditioning - Hummer H2

  

REFRIGERANT SYSTEM CAPACITIES

Refrigerant System Capacities 

DIAGNOSTIC INFORMATION AND PROCEDURES 

DIAGNOSTIC STARTING POINT - HEATING, VENTILATION AND AIR CONDITIONING 

The Heating, Ventilation and Air Conditioning (HVAC) system is divided into two sections. The first, Heating, 
Ventilation and Air Conditioning, it has all of the replacement procedures that pertain to the HVAC components 
or functions that are associated with an automatic control system. The second, HVAC Systems-Automatic, has 
all of the diagnostic procedures specific to the automatic control system. 

For systems with DTCs, begin the system diagnosis with the following procedures: Diagnostic System Check -
HVAC Systems - Automatic in HVAC Systems-Automatic 

The Diagnostic System Check will provide the following information: 

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The identification of the control modules which command the system.  

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The ability of the control modules to communicate through the class 2 serial data circuit.  

The use of the Diagnostic System Check will identify and lead the technician to the correct diagnostic 
procedure. 

Review the Description and Operation information to help you determine the correct symptom diagnostic 
procedure when a malfunction exists. Reviewing the Description and Operation information will also help you 
determine if the condition described by the customer is normal operation. The HVAC Description and 
Operation information is divided into: 

Application

Specification

Metric

English

PAG Oil GM P/N 12378526 for United States 
PAG Oil GM P/N 88900060 for Canada
Accumulator Replacement

-ml*

-oz*

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*Add 60 ml (2 oz) of PAG oil, plus the equal amount of oil drained from the accumulator.  

Compressor Replacement

60 ml

2 oz

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The Denso replacement compressor is precharged with 237 ml (8.0 oz) of PAG oil.  

Condenser Replacement

30 ml

1 oz

Evaporator Replacement

90 ml

3 oz

If more than the specified amount of PAG oil was drained from a component, add the equal amount 
drained.

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Total System PAG Oil Capacity  

210 ml

7.1 oz

R-134a

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Refrigerant Charge  

0.7 kg

1.6 lb

 

2004 Hummer H2 

2004 HVAC Heating, Ventilation and Air Conditioning - Hummer H2

  

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Air Delivery Description and Operation in HVAC Systems-Automatic  

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Air Temperature Description and Operation in HVAC Systems-Automatic  

The Air Delivery Description and Operation contains the following topics: 

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HVAC Control Components  

z

Air Speed  

z

Air Delivery  

z

Recirculation Operation  

z

Automatic Operation  

The Air Temperature Description and Operation contains the following topics: 

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HVAC Control Components  

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Heating and A/C Operation  

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Automatic Operation  

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Engine Coolant  

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A/C Cycle  

LEAK TESTING 

Tools Required 

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J 39400-A Halogen Leak Detector. See Special Tools and Equipment .  

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J 41447 R-134a A/C Tracer Dye - Box of 24. See Special Tools and Equipment .  

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

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J 43872 Fluorescent Dye Cleaner. See Special Tools and Equipment .  

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J 46297 A/C Dye Injector Kit. See Special Tools and Equipment .  

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J 46297-12 Replacement Dye Cartridges. See Special Tools and Equipment .  

Refrigerant Leak Testing 

The fluorescent dye mixes and flows with the polyalkylene glycel (PAG) oil throughout the refrigerant system. 

Verifying some passive leaks may require using the J 39400-A , even though the A/C system contains 
fluorescent dye. See Special Tools and Equipment . 

The only time that adding additional fluorescent dye is required is after flushing the A/C system.

IMPORTANT: General Motors vehicles are now manufactured with fluorescent dye installed 

directly into the air conditioning (A/C) system.

 

2004 Hummer H2 

2004 HVAC Heating, Ventilation and Air Conditioning - Hummer H2

  

Fluorescent Leak Detector 

Fluorescent dye will assist in locating any leaks in the A/C system. 

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Condensation on the evaporator core or the refrigerant lines may wash the PAG oil and fluorescent dye 
away from the actual leak. Condensation may also carry dye through the HVAC module drain.  

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Leaks in the A/C system will be indicated in a light green or yellow color when using the leak detection 
lamp. 

Use the leak detection lamp in the following areas: 

{

All fittings or connections that use seal washers or O-rings  

{

All of the A/C components  

{

The A/C compressor shaft seal  

{

The A/C hoses and pressure switches  

{

The HVAC module drain tube, if the evaporator core is suspected of leaking  

{

The service port sealing caps 

The sealing cap is the primary seal for the service ports. 

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Follow the instructions supplied with the J 42220 . See Special Tools and Equipment .  

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To prevent false diagnosis in the future, thoroughly clean the residual dye from any area where leaks were 
found. Use a rag and the approved fluorescent dye cleaner J 43872 . See Special Tools and Equipment . 

Fluorescent Dye Injection 

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Not all of the fluorescent dyes are compatible with PAG oil. 

Some types of dye decrease the oil viscosity or may chemically react with the oil. 

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R-134a leak detection dye requires time to work. Depending upon the leak rate, a leak may not become 
visible for between 15 minutes and 7 days. 

IMPORTANT: PAG oil is water soluble.

IMPORTANT: Use only fluorescent dye approved by General Motors. 

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J 41447 can be poured directly into a removed A/C component. See 
Special Tools and Equipment .  

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J 46297-12 is injected into the low side port using J 46297 . See 
Special Tools and Equipment .  

IMPORTANT: Do NOT overcharge the A/C system with dye. Use only one 7.39 ml (0.25 

oz) charge.

 

2004 Hummer H2 

2004 HVAC Heating, Ventilation and Air Conditioning - Hummer H2