Test Procedure

CAUTION: Take care to prevent personal injury which could occur due to touching a hot engine when testing. Tests should be done with the engine "Off" and as cool as possible. Do not operate the detector in a combustible atmosphere since its sensor operates at high temperature.

IMPORTANT: Always follow the refrigerant system around in a continuous path, so that no areas of potential leaks are missed. Always test all of the areas mentioned to ensure that the entire system is leak-free, even when one leak is already found.

Service Ports/Access Valves
The primary seal for the service ports is the sealing cap. This cap contains a special O-ring seal or gasket designed to provide a leak-free seal. If the sealing cap is loose or missing, or the wrong cap is used, a loss of the refrigerant charge will result.

Evaporator Core
Finding leaks in the evaporator core is very difficult. Leak test the core as follows:
1. Turn the blower fan to the HIGH position for 15 seconds or longer.
Then, turn the blower fan OFF.
2. Wait 10 minutes.
3. Remove the blower motor resistor. Refer to Blower Motor Resistor Replacement or Blower Motor Resistor Replacement (RPO YG6) or Blower Motor Resistor Replacement (RPO C60). SEE Blower Motor Resistor Service and Repair
4. Insert the leak detector probe as close to the evaporator as possible.
The detector will sound a solid alarm if a leak is found.
5. If possible, visually inspect the core face with a flashlight for evidence of refrigerant oil.

Compressor Block Fitting and Shaft Seal
Test the compressor block fitting and shaft seal as follows:
1. Blow shop air behind and in front of the compressor clutch/pulley for at least 15 seconds.
2. Wait 5 minutes.
3. Probe the area in front of the pulley.
A solid alarm indicates the discovery of a leak.

For a description of the RPO Code(s) shown in this article/images refer to the RPO Code List found at Vehicle/Application ID RPO Codes