R-12 Systems

System performance test must be performed with an ambient temperature of approximately 95°F.

1. Run engine at 1500 RPM.
2. Ensure A/C switch is at the On position and the blower motor is at the High position.
3. Set temperature control lever to the Max Cold position.
4. Connect manifold gauge. Low pressure hose is connected to Suction side and high pressure hose is connected to Discharge side.
5. Normal low pressure should read 21-28 psi.
6. Normal high pressure should read 199-213 psi.

Fig. 1 R-12 System Diagnosis (Part 1 Of 2):

Fig. 1 R-12 System Diagnosis (Part 2 Of 2):

7. If pressure readings are not as specified, refer to Fig. 1 for diagnosis.