On Car Inspection

Manifold Gage Set:

1. Install manifold gage set as shown in the illustration.

2. Close Hi and Low hand valves.

3. Run engine at fast idle.

4. Check compressor for following:

a. High pressure gage reading is not low and low pressure gage reading is not higher than normal.

NOTICE If the low pressure side reads too high or the high pressure side too low, the probable cause is leakage from the reed valve inside the compressor or a broken sliding part (piston, cylinder, or others). In such a case, disassembly of the compressor will be necessary.

b. Metallic sound.
c. Leakage from shaft seal.

If any of the above checks indicate a defect, repair the compressor.

5. Check magnetic clutch.

a. Inspect the pressure plate and the rotor for signs of oil.
b. Check the clutch bearings for noise and grease leakage.
c. Using an ohmmeter, measure the resistance of the stator coil between the clutch lead wire and ground at 25°C (77°F). If the resistance is not within tolerance, replace the coil.
d. The standard resistance has a valve of 3.2 ± 0.2 ohms.