Refrigerant Level Test

1. Clean refrigerant level sight glass, then start engine.
2. Push A/C button to operate compressor, place blower switch to high position and move temperature lever to the extreme left.
3. Allow system to operate for several minutes, then check sight glass as follows:
a. If sight glass is clear, magnetic clutch is engaged, compressor discharge line is warm and compressor inlet line is cool, the system has a full charge.
b. If sight glass is clear, magnetic clutch is engaged and there is no difference in temperature between compressor inlet and discharge lines, the system has lost some refrigerant.
c. If sight glass is clear and magnetic clutch is disengaged, clutch is defective or system is out of refrigerant.
d. If foam or bubbles are present in sight glass, system could be low on refrigerant. Occasional foam or bubbles are normal when temperature is above 110°F or below 70°F.

4. Allow engine to run at 1500 RPM, then block airflow through condenser to increase compressor discharge pressure to 206-220 psi. If foam or bubbles are still present in sight glass, system is low on refrigerant. The refrigerant system should not be low on charge unless there is a leak. Repair leak as required, then repeat test.