R-12 Systems

Testing the refrigerant system for leaks is one of the most important phases of troubleshooting. Several types of leak detectors are available that are suitable for detecting A/C system leaks. One or more of the following procedures will prove useful for detecting leaks and checking connections after service work has been performed. Prior to performing any leak test, prepare the vehicle as follows:
1. Attach a suitable gauge manifold to system and observe pressure readings.
2. If little or no pressure is indicated, the system must be partially charged.
3. If gauges indicate pressure, set engine to run at fast idle and operate system at maximum cooling for 10-15 minutes, then stop engine and perform leak tests.