1B-4 AIR CONDITIONING This oil is supplied to the cylinders, bearings, etc., by an oil pump which is connected to the swash plate shaft. With some compressors the differential between the in- take pressure and discharge pressure generated while the compressor is operating is used for lubrication in- stead of an oil pump. The specified amount of compressor oil is 180cc (5.0 Imp fl oz). The oil used in the R-134a system compressor differs from that used in R-12 systems. Also, compressor oil to be used varies according to the compressor model. Be sure to avoid mixing two or more different types of oil.
If the wrong oil is used, lubrication will be poor and the compressor will seize or malfunction. (Refer to “ON-VEHICLE SERVICE” for Precautions for R-134a Air Conditioning System in this section) The magnetic clutch connector is a waterproof type. A condenser (1) may malfunction in two ways: it may leak, or it may be restricted. A condenser restriction will result in excessive compressor discharge pressure. If a partial restriction is present, the refrigerant expands af- ter passing through the restriction. Thus, ice or frost may from immediately after the restric- tion. If air flow through the condenser or radiator is blocked, high discharge pressures will result.
During normal condenser operation, the refrigerant outlet line will be slightly cooler than the inlet line. The vehicle is equipped with the condenser of the paral- lel flow type condenser. A larger thermal transmission area on the inner surface of the tube allows the radiant heat to increase and the ventilation resistance to de- crease. Magnetic Clutch The compressor (1) is driven by the drive belt from the crank pulley of the engine. If the compressor is activated each time the engine is started, this causes too much load to the engine. The magnetic clutch (2) transmits the power from the engine to the compressor and activates it when the air conditioning is “ON”.
Also, it cuts off the power from the engine to the compressor when the air conditioning is “OFF”. (Magnetic clutch repair procedure can be found in Section 1D) 1 N1A0047E 1 2 Receiver/Drier The receiver/drier performs four functions; As the quantity of refrigerant circulated varies de- pending on the refrigeration cycle conditions, suffi- cient refrigerant is stored for the refrigeration cycle to operate smoothly in accordance with fluctua- tions in the quantity circulated. The liquefied refrigerant from the condenser is mixed with refrigerant gas containing air bubbles. If refrigerant containing air bubbles is sent to the ex- pansion valve, the cooling capacity will decrease considerably.
Therefore, the liquid and air bubbles are separated and only the liquid is sent to the ex- pansion valve. N1A0046E Condenser The condenser assembly in front of the radiator, which carry the refrigerant and cooling fins to provide rapid transfer of heat. Also, it functions to cool and liquefy the high-pressure and high-temperature vapor sent from the compressor by the radiator fan or outside air. The receiver/drier utilizes a filter and dryer to re- move the dirt and water mixed in the cycling refrig- erant. A receiver/drier may fail due to a restriction inside the body of the unit. A restriction at the inlet to the receiver/ drier will cause high pressures.
Outlet restrictions will be indicated by low pressure and little or no cooling. An excessively cold receiver/drier outlet may indicate a restriction.