Check refrigerant sight glass after unit has been operating 15 minutes refrigerant should be clear without any indication of foaming. If refrigerant is foaming, have refrigerant added by serviceman. Call to the attention of refrigeration service man any malfunction of the condensor fan motor. Check oil level weekly. Fill with correct type of oil recommended by manufacturer.
Some oils contain additives which form a sludge when mixed with water and detergent.
Do not overfill - excess oil will blow out exhaust. Check type and tension of belts. Spin pump by hand to see if vanes fall freely, or to detect unusual drag loose pulleys or rough bearings. Check that pulleys are in line. With v-belts care must be taken that the belt section used matches the the correct section pulley, for example, B section belting should not be use on A section pulleys.