Trouble Diagnosis For Abnormal Pressure

Whenever system's high and/or low side pressure is abnormal, diagnose using a manifold gauge. The marker above the gauge scale indicates the standard (normal) pressure range. Since the standard (normal) pressure, however, differs from vehicle to vehicle, See ("Ambient air temperature-to-operating pressure table").





Both High and Low-pressure Sides are Too High.

High-pressure Side is Too High and Low-pressure Side is Too Low.

High-pressure Side is Too Low and Low-pressure Side is Too High.

Both High- and Low-pressure Sides are Too Low.

Low-pressure Side Sometimes Becomes Negative.

Low-pressure Side Becomes Negative.