Chevrolet Silverado / GMC Sierra. Service manual — part 2297

REFRIGERANT SYSTEM CAPACITIES

Compressor Suction Hose to Accumulator

41 N.m

30 lb ft

Condenser Upper Insulator Retainer Bolts

2.4 N.m

21 lb in

Discharge Hose Mounting Bolt (LR4, LM7, LQ4
Denso)

16 N.m

12 lb ft

Evaporator Tube Fitting at Orifice

25 N.m

18 lb ft

Evaporator Tube Nut at Condenser

16 N.m

12 lb ft

Evaporator Tube Nut at Evaporator

16 N.m

12 lb ft

Evaporator Tube to the Auxiliary A/C Tube

16 N.m

12 lb ft

Filter Access Door Screw

1.6 N.m

14 lb in

Floor Air Outlet Duct Screw

1.6 N.m

14 lb in

Heater A/C Auxiliary Tubes Retaining Nuts

7 N.m

62 lb in

Heater Core Cover Screws

1.6 N.m

14 lb in

Heater Hose Outlet Mounting Nut and Bolt

25 N.m

18 lb ft

Heater/Ventilation Module Mounting Nuts

9 N.m

80 lb in

Heater/Ventilation Module Mounting Screws

4 N.m

35 lb in

Heater Ventilation Module Screws

1.6 N.m

14 lb in

Insulator Retainers and Bolts

2.4 N.m

21 lb in

Pressure Relief Valve

9 N.m

80 lb in

Suction Hose Mounting Bolt (LR4, LM7, LQ4
Denso)

16 N.m

12 lb ft

Application

Specification

Metric

English

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

60 ml*

2 oz*

* Add PAG oil equal to the amount of oil drained from the accumulator plus the
specified additional amount.

Compressor Replacement

60 ml

1

2 oz

1

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

Condenser Replacement

30 ml

1

1 oz

1

Evaporator Replacement

90 ml

1

3 oz

1

2008 Chevrolet Silverado 1500

2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

DIAGNOSTIC INFORMATION AND PROCEDURES

DIAGNOSTIC STARTING POINT - HEATING, VENTILATION AND AIR CONDITIONING

Begin the system diagnosis with Diagnostic System Check - Vehicle . The Diagnostic System
Check - Vehicle will provide the following information:

The identification of the control modules which are not communicating.

The identification of any stored diagnostic trouble codes (DTCs) and their status.

The use of the Diagnostic System Check - Vehicle will identify the correct procedures to begin
vehicle diagnosis. These must be performed before system DTC or symptom diagnosis.

LEAK TESTING

Tools Required

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

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

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

J 43872 Fluorescent Dye Cleaner. See Special Tools.

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

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

Evaporator, Rear Replacement

90 ml

1

3 oz

1

Total System PAG Oil Capacity

210 ml

7.1 oz

Total System PAG Oil Capacity with Rear
A/C

330 ml

11 oz

R-134a

Refrigerant Charge

0.7 kg

1.6 lb

Refrigerant Charge Utility with Front and Rear
A/C

1.13 kg

2.5 lb

Refrigerant Charge Suburban with Front and
Rear A/C

1.4 kg

3.0 lb

1

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

equal amount of oil drained.

2008 Chevrolet Silverado 1500

2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

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. See Special Tools.

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.

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 . See Special Tools.

IMPORTANT: General Motors vehicles are now manufactured with fluorescent

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

IMPORTANT: PAG oil is water soluble.

2008 Chevrolet Silverado 1500

2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

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.

To prevent false diagnosis, thoroughly clean any residual dye from the service port with a
rag and the approved fluorescent dye cleaner J 43872 . See Special Tools.

Halogen Leak Detector

Ensure that the vehicle has at least 0.45 kg (1 lb) of refrigerant in the A/C refrigeration system in
order to perform a leak test. Refer to Refrigerant Recovery and Recharging for recharging the
A/C system.

Clean and dry all surfaces in order to prevent a false warning. Liquids will damage the detector.

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

7.39 ml (0.25 oz) charge.

CAUTION: Do not operate the detector in a combustible atmosphere

since its sensor operates at high temperatures or personal
injury and/or damage to the equipment may result.

IMPORTANT: Halogen leak detectors are sensitive to the following items:

Windshield washing solutions

Many solvents and cleaners

Some adhesives used in the vehicle

IMPORTANT: Follow a continuous path in order to ensure that you will not miss

2008 Chevrolet Silverado 1500

2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado