System Performance Test

A/C Pressures And Clutch Cycle Time Operation Chart:

A/C Evaluation Chart:

Refrigerant system problems are diagnosed by checking refrigerant pressures and clutch cycle rate and times. Compare pressures and cycle time to charts shown. Conditional requirements for refrigerant systems tests must be satisfied to obtain accurate pressure readings. If findings do not fall between lines of respective charts, refer to A/C System Evaluation Chart to determine cause of improper readings. Refrigerant System Pressure Evaluation Chart

After necessary repairs have been performed, take pressure readings while meeting conditional requirements to ensure problem has been corrected. Visual inspection of the system may determine some of the following problems:
- Obstructed air passages
- Broken wires
- Loose or broken mounting brackets and refrigerant leaks.

NOTE: A refrigerant leak will usually appear as an oily residue at the leakage point in the system.