Manifold Gauge Set Readings
After you locate the defective component contain-
ing the restriction, recover all of the refrigerant.
Replace the defective component and the receiver-
drier. Evacuate and recharge the system with re-
frigerant, then check AC operation and perfor-
Gauge reading, compressor
The compressor may be noisy when it operates.
Defective reed valves or other compressor compo-
nents. If the compressor is not noisy, there may be
a worn or loose compressor clutch drive belt.
If you find the belt worn or loose, replace or tighten
it and recheck system performance and gauge
you must isolate (front seat the stem type compres-
sor service valves) and recover refrigerant, or fully
recover R-12 from systems containing Schrader
valves. Remove the compressor cylinder head and
check the appearance of the reed valve plate as-
sembly. If defective, replace the valve plate and
install with new gaskets, or replace the compres-