Hummer H3. Manual — part 1251

2007 HVAC

Heating, Ventilation and Air Conditioning - H3

SPECIFICATIONS

FASTENER TIGHTENING SPECIFICATIONS

Fastener Tightening Specifications

REFRIGERANT SYSTEM CAPACITIES

Refrigerant System Capacities

Application

Specification

Metric

English

A/C Compressor Mounting Bolt

50 N.m

37 lb ft

A/C Refrigerant Pressure Sensor

4.8 N.m

42 lb in

Air Distributor Duct Mounting Screw

1.9 N.m

17 lb in

Air Inlet Assembly Mounting Stud

4.5 N.m

40 lb in

Blower Motor and Fan Assembly Mounting Screw

1.9 N.m

17 lb in

Blower Motor Relay Bracket Mounting Screw

1.9 N.m

17 lb in

Blower Motor Resistor Mounting Screw

1.9 N.m

17 lb in

Compressor Discharge Hose to Condenser Fitting

28 N.m

21 lb ft

Compressor Suction and Discharge Hose to
Compressor

33 N.m

24 lb ft

Compressor Suction Hose to TXV

48 N.m

35 lb ft

Evaporator Case Section to Blower Case Section
Retaining Screw

1.9 N.m

17 lb in

Evaporator Tube to Condenser Fitting

28 N.m

21 lb ft

Floor Air Outlet Mounting Screw

1.9 N.m

17 lb in

Heater Core Access Cover Screw

1.9 N.m

17 lb in

Heater Inlet and Outlet Hoses Bracket Bolt

25 N.m

18 lb ft

Heater/Vent Module Mounting Nut

4.5 N.m

40 lb in

Heater/Vent Module Mounting Screw

4.5 N.m

40 lb in

Heater/Vent Module Mounting Stud

4.5 N.m

40 lb in

Receiver Drier Clamp Screw

10 N.m

88 lb in

Specification

2007 Hummer H3

2007 HVAC Heating, Ventilation and Air Conditioning - H3

2007 Hummer H3

2007 HVAC Heating, Ventilation and Air Conditioning - H3

DIAGNOSTIC INFORMATION AND PROCEDURES

DIAGNOSTIC STARTING POINT - HEATING, VENTILATION AND AIR CONDITIONING

The Heating, Ventilation and Air Conditioning (HVAC) system is divided into 2 separate
sections. The first, Heating, Ventilation and Air Conditioning, has all procedures that pertain to a
HVAC component or function that is not specifically associated with the manual control system.
The second, HVAC Systems - Manual, has all procedures specific to the Manual control system.

Begin the system diagnosis with the Diagnostic System Check - Vehicle .

The Diagnostic System Check will provide the identification of the control modules which
command the system.

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the
system and where the procedure is located.

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:

Air Delivery Description and Operation

Air Temperature Description and Operation

The Air Delivery Description and Operation contains the following topics:

Application

Metric

English

PAG Oil GM P/N 12378526 (Canadian P/N 88900060)

The Denso service compressor is precharged with 74 ml (2.5 oz.) of PAG oil.

Receiver Dryer Replacement

23 ml*

0.8 oz.*

*Add the same amount of PAG oil drained from the failed receiver dryer, plus the
specified amount.

Condenser Replacement

44 ml

1

1.5 oz.

1

Evaporator Replacement

15 ml

1

0.5 oz.

1

Total System Oil Capacity

119 ml

4 oz.

Refrigerant Charge

0.68 kg

1.5 lb

2007 Hummer H3

2007 HVAC Heating, Ventilation and Air Conditioning - H3

HVAC Control Components

Air Speed

Air Distribution

Recirculation Operation

The Air temperature Description and Operation contains the following topics:

HVAC Control Components

Heating and A/C Operation

Engine Coolant

A/C Cycle

LEAK TESTING

Tools Required

J 39400-A Halogen Leak Detector

J 41447 Leak Detection Dye. See Special Tools.

J 42220 Leak Detection Lamp. See Special Tools.

J 43872 Fluorescent Dye Cleaner

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

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

Refrigerant Leak Testing

The fluorescent dye mixes and flows with the polyalkylene glycol (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.

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

Fluorescent Leak Detector

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

IMPORTANT: General Motors vehicles are now manufactured with fluorescent

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

2007 Hummer H3

2007 HVAC Heating, Ventilation and Air Conditioning - H3

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.

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.

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

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 J 43872 .

Fluorescent Dye Injection

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.

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.

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

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

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

2007 Hummer H3

2007 HVAC Heating, Ventilation and Air Conditioning - H3