Compressor Description
Vehicles using V5 compressor may have differences between installations in mounting brackets, drive systems, pulleys, connections, and system capacities. Basic overhaul procedures are similar between compressors used on different vehicles.
When servicing compressor, keep dirt and foreign material from getting on or into compressor parts and system. Clean tools and a clean work area are important for proper service. The compressor connections and outside of compressor should be cleaned before performance of any on-vehicle repairs and before removal of compressor. The parts must be kept clean at all times and any parts that are to be reassembled should be cleaned with trichloroethane, naphtha, stoddard solvent, kerosene or equivalent solvents and dried with dry air. Use only lint-free cloths to wipe parts.
The operations described are based on bench overhaul with compressor removed from vehicle, except as noted. They have been prepared in order of accessibility of components. When a compressor is removed from vehicle for servicing, amount of oil remaining in compressor should be drained, measured and recorded. This oil should then be discarded and new PolyAlkalene Glycol (PAG) refrigerant oil added to compressor.
Note. The oil drain plug must be removed and oil drained through plug opening to ensure complete draining of oil from compressor.
Compressor Operation
The V5 is a variable displacement compressor that can match automotive air conditioning demand under all conditions without cycling. The basic compressor mechanism is a variable angle wobble-plate with 5 axiallyoriented cylinders. The center of control of compressor displacement is a billows-actuated control valve located in rear head of compressor that senses compressor suction pressure.
The wobble-plate angle and compressor displacement are controlled by crankcase suction pressure differential. When A/C capacity demand is high, suction pressure will be above control point. The valve will maintain a bleed from crankcase to suction. With no crankcase-suction pressure differential, compressor will have maximum displacement. When A/C capacity demand is lower and suction pressure reaches control point, valve will bleed discharge gas into crankcase and close off a passage from crankcase to suction plenum. The angle of wobble-plate is controlled by a force balance on 5 pistons.
A slight elevation of crankcase suction pressure differential creates total force on pistons resulting in a movement about wobble-plate pivot pin that reduces plate angle. The compressor has a unique lubrication system. The crankcase suction bleed is routed through rotating wobble-plate for lubrication of wobble-plate bearing. The rotation acts as an oil separator which removes some of oil from crankcase suction bleed, re-routing it to crankcase where it can lubricate compressor mechanism.