Avalanche, Sierra, Silverado, C&K Series, 1999-2005

Testing The System

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Leak Testing



The following tools may be required



J 39400-A Halogen Leak Detector
 
J 41447 R-134a A/C Tracer Dye-Box of 24
 
J 42220 Universal 12 V Leak Detection Lamp
 
J 43872 Fluorescent Dye Cleaner
 
J 46297 A/C Dye Injector Kit
 
J 46297-12 Replacement Dye Cartridges
 

The following tools may be required



J 39400-A Halogen Leak Detector
 
J 41447 R-134a A/C Tracer Dye-Box of 24
 
J 42220 Universal 12 V Leak Detection Lamp
 
J 43872 Fluorescent Dye Cleaner
 
J 46297 A/C Dye Injector Kit
 
J 46297-12 Replacement Dye Cartridges
 

The following tools may be required



J 39400-A Halogen Leak Detector
 
J 41447 R-134a A/C Tracer Dye-Box of 24
 
J 42220 Universal 12 V Leak Detection Lamp
 
J 43872 Fluorescent Dye Cleaner
 
J 46297 A/C Dye Injector Kit
 
J 46297-12 Replacement Dye Cartridges
 

Fluorescent Dye Leak Detection

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


NOTE
PAG oil is water soluble. 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.

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.

Only use dyes approved for use with General Motors vehicles. 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. To put the dye into the A/C circuit:



J-41447 can be poured directly into a removed A/C component
 
J-46297-12 is injected into the low side port using J-46297
 

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.


WARNING
DO NOT overcharge the A/C system with dye. Use only one 0.25 oz (7.39 ml) charge.

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

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


NOTE
Observe the following:



J41447 is the only dye approved by General Motors. Not all of the R-134a dyes are compatible with PAG oil. Some dyes decrease the oil viscosity or chemically react with the oil.
 
PAG oil is water soluble. Condensation may form on the refrigerant lines or on the evaporator core. This condensation may wash the PAG oil or the leak dye off of the line or off the core and out through the condensation drain. Condensation may make some leaks harder to find using the dye detector. Fluorescence at the drain opening indicates a core leak.
 
R-134a tracer dye requires time in order to work. Depending upon the leak rate, a leak may not become visible for between 15 minutes and 7 days.
 
The dye, when mixed with the PAG oil, remains detectable in the system for 2 years. Do not double the system using dye. This may cause reliability problems. Use only a 0.25 oz charge.
 
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.
 

To prevent false diagnosis in the future, thoroughly clean the residual dye from any area where leaks were found. Use a rag and an approved fluorescent dye cleaner.

Only use dyes approved for use with General Motors vehicles. 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. To put the dye into the A/C circuit:



J-41447 can be poured directly into a removed A/C component
 
J-46297-12 is injected into the low side port using J-46297
 

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.


WARNING
DO NOT overcharge the A/C system with dye. Use only one 0.25 oz (7.39 ml) charge.

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

Only use dyes approved for use with General Motors vehicles. 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. To put the dye into the A/C circuit:



J-41447 can be poured directly into a removed A/C component
 
J-46297-12 is injected into the low side port using J-46297
 

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.


WARNING
DO NOT overcharge the A/C system with dye. Use only one 0.25 oz (7.39 ml) charge.

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

Halogen Leak Detector

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.

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

Halogen leak detectors are sensitive to the following:



Windshield washing solutions
 
Many solvents and cleaners
 
Some adhesives used in the vehicle
 

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

Follow a continuous path in order to ensure that you will not miss any possible leaks. Test all areas of the system for leaks.

Follow the instructions supplied with the J-39400-A.

A halogen leak detector is the most useful tool for locating refrigerant leaks. Tool J39400 provides an audible signal which increases in frequency as the unit detects R-134a. Follow the instructions included with the unit in order to properly calibrate the instrument. Use the detector in the proper setting for the type of tested refrigerant. Set the detector gas switch to R-134a prior to use.

The most common leaks occur at the refrigerant fittings or connections. The leaks may be the result of any of the following conditions:



Improper torque
 
Damaged O-rings
 
Lack of lubricant on the O-rings
 
Dirt or debris across the O-ring
 
Small pieces of lint from cotton gloves or shop cloths on the O-ring
 

In order to successfully use tool J39400 or any other electronic leak detector, maintain a proper scan rate. Carefully follow the manufacturer's instructions regarding calibration, operation, and maintenance.

During testing, completely circle each joint using the probe at a rate of at 51 mm (1-2 in) per second. Place the tip of the probe less than 6 mm (0.25 in) away from the surface. Do not block the probe tip air intake. A leak exists when the audible tone changes from a steady 1-2 clicks per second to a continuous alarm. Frequently adjust the balance knob in order to maintain the rate of 1-2 clicks per second.


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.

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.


NOTE
 Halogen leak detectors are sensitive to the following items:



Windshield washing solutions
 
Many solvents and cleaners
 
Some adhesives used in the vehicle
 

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

  1. Use this procedure in order to test the following components:
    NOTE
     Follow a continuous path in order to ensure that you will not miss any possible leaks. Test all areas of the system for leaks.



    The evaporator inlet
     
    The evaporator outlet
     
    The accumulator inlet
     
    The accumulator outlet
     
    The condenser inlet
     
    The condenser outlet
     
    All brazed joints
     
    All welded joints
     
    The compressor rear head
     
    The housing joints
     

  2.  


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.

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

Halogen leak detectors are sensitive to the following:



Windshield washing solutions
 
Many solvents and cleaners
 
Some adhesives used in the vehicle
 

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

Follow a continuous path in order to ensure that you will not miss any possible leaks. Test all areas of the system for leaks.

Follow the instructions supplied with the J-39400-A.


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.

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

Halogen leak detectors are sensitive to the following:



Windshield washing solutions
 
Many solvents and cleaners
 
Some adhesives used in the vehicle
 

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

Follow a continuous path in order to ensure that you will not miss any possible leaks. Test all areas of the system for leaks.

Follow the instructions supplied with the J-39400-A.

Refrigerant Leak Testing

NOTE
General Motors vehicles are now manufactured with fluorescent dye installed directly into the A/C system.

The fluorescent dye mixes and flows with the 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.

 
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