Leak Testing
Refrigerant Leak Testing
Note: General Motors
vehicles are now manufactured with fluorescent dye installed
directly into the air conditioning (A/C) system.
Note: Directive 2006/40/EC:
If a higher amount of refrigerant escaped, the needed repair has to
be accomplished before the air condition is filled with refrigerant
(Article 6 section 3 and 3 chemicals climate protection order).
The fluorescent dye mixes and flows with the polyalkylene glycol
(PAG) oil throughout the refrigerant system.
Verifying some passive leaks may require using a halogen leak
detector, even though the A/C system contains fluorescent dye.
The only time 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.
|
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 detection lamp. |
• |
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. |
Fluorescent Dye Injection
Note: Use only fluorescent
dye approved by General Motors.
• |
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. |
|
Note: Do NOT
overcharge the A/C system with dye.
|
• |
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 an approved fluorescent dye cleaner. |
Halogen Leak Detector
|
Warning:
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. Refer to
Refrigerant Recovery and Recharging .
Note: Halogen leak
detectors are sensitive to the following items:
• |
Some adhesives
used in the vehicle |
• |
Many solvents and
cleaners |
• |
Windshield washing
solutions |
Clean and dry all surfaces in order to prevent a false warning.
Liquids will damage the detector.
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.
Follow the instructions supplied with the halogen leak
tester.
Leak Detection with Nitrogen
If a leak test with fluorescent leak detector nor halogen leak
detector is not possible, then a leak test with nitrogen has to
take place. Therefore the air condition leak detector nitrogen kit
+ has to be used.
The nitrogen escapes on a leak and with the use of soap sud or a
special leak detection spray could be made visible due to upcoming
bubbles.
|