AIR CONDITIONING SYSTEM — Troubleshooting AC-7 7. AIR PRESENT IN REFRIGERATION SYSTEM Condition: Does not cool down sufficiently NOTE: These gauge indications are shown when the refrigeration system has been charged with refrigerant charged without vacuum purging. Symptom seen in refrigeration system Probable cause Diagnosis Remedy Pressure too high at both Air entered in refrigeration Air present in refrigeration (1) Replace receiver and low and high pressure sides system system drier (2) Check compressor oil Insufficient vacuum to see if dirty or in- purging sufficient (3) Vacuum purge and charge new refrigerant 8. REFRIGERANT DOES NOT CIRCULATE Condition: Does not cool (Cools from time to time in some cases) Symptom seen in refrigeration system Probable cause Diagnosis Remedy Vacuum indicated at high Refrigerant flow obstructed Expansion valve orifice Allow to stand for some time pressure side, very low by moisture or dirt in clogged and then restart operation pressure indicated at high receiver or foreign matter to determine if trouble is pressure side adhering to expansion valve Refrigerant does not flow caused by moisture or dirt If caused by moisture refer Frost or dew seen on piping Refrigerant flow obstructed to step 2 on page AC-4 before and after receiver by gas leakage from expan- If caused by dirt, remove and drier or expansion valve sion valve heat sensing tube expansion valve and clean off dirt by blowing with air. If unable to remove dirt, replace valve. Vacuum purge and charge new refrigerant to proper amount If gas leakage from heat sensing tube, replace expan- sion valve