Compressor P72

The P72 chassis uses the Harrison R4 compressor. The compressor is driven by a serpentine belt from the engine crankshaft through the compressor clutch pulley. The compressor pulley rotates freely without turning the compressor shaft until an electromagnetic clutch coil is energized. When voltage is applied to the clutch coil, the clutch plate and hub assembly is drawn rearward toward the pulley. The magnetic force locks the clutch plate and the pulley together as one unit to drive the compressor shaft.

New compressors have oil in the crankcase. Drain and keep the oil. The amount of oil put in the new compressor must be the same amount that was in the old comressor. Refer to Compressor Specifications Compressor Specifications (P72).

Compressor P92

The P92 chassis uses the Seltec TM-16HD compressor. The compressor is driven by a serpentine belt from the engine crankshaft through the compressor clutch pulley. The compressor pulley rotates freely without turning the compressor shaft until an electromagnetic clutch coil is energized. When voltage is applied to the clutch coil, the clutch plate and hub assembly is drawn rearward toward the pulley. The magnetic force locks the clutch plate and the pulley together as one unit to drive the compressor shaft.

New Seltec compressors are filled with the amount of oil that is listed on an information plate on the compressor housing. They are also filled with nitrogen (N2) gas. Refer to Handling Air Conditioning (A/C) Compressor Handling the Compressor.