Servicing Precautions
Care must be taken when handling refrigeration system components. Units must not be lifted by their hoses, pipes or capillary lines. Hoses and lines must not be subjected to any twist or stress. Ensure that hoses are positioned in their correct run before fully tightening the couplings, and ensure that all clips and supports are used. Torque wrenches of the correct type must be used when tightening refrigerant connections to the stated value. An additional wrench must be used to hold the union to prevent twisting of the pipe.
Before connecting any hose or pipe ensure that refrigerant oil is applied to the seat of the new 'O' ring but not to the threads.
Check the oil trap for the amount of oil lost. All protective plugs on components must be left in place until immediately prior to connection.
The receiver/drier contains desiccant which absorbs moisture It must be positively sealed at all times.
CAUTION: Whenever the refrigerant system is opened, the receiver/drier must be renewed immediately before evacuating and recharging the system.
Use alcohol and a clean cloth to clean dirty connections.
Ensure that all new parts fitted are marked for use with R134a.
Refrigerant oil
Use the approved refrigerant lubricating oil:
Nippon Denso ND-OIL 8
Unipart R134a ND-OIL 8
CAUTION: Do not use any other type of refrigerant oil.
Refrigerant oil easily absorbs water and must not be stored for long periods. Do not pour unused oil back into the container.
When renewing system components, add the following quantities of refrigerant oil:
Condenser 40 ml
Evaporator 80 ml
Pipe or hose 20 ml
Receiver/drier 20 ml
Total of refrigerant oil in system = 180 ml = 6.3 Fl oz
A new compressor is sealed and pressurised with Nitrogen gas, slowly release the sealing cap. gas pressure should be heard to release as the seal is broken.
NOTE: A new compressor should always have its sealing caps in place and must not be removed until immediately prior to fitting
Fitting a new compressor
A new compressor is supplied with an oil fill (X) of: 180 ml
A calculated quantity of oil must be drained from a new compressor before fining.
To calculate the quantity of oil to be drained:
1. Remove sealing plugs from the OLD compressor
2. Invert compressor and gravity drain oil into measuring cylinder. Rotating the compressor clutch plate will assist complete draining.
3. Note the quantity of oil drained (Y).
4. Calculate the quantity (Q) of oil to be drained from the NEW compressor using the following formula:
X - (Y + 20 ml) = Q
Rapid refrigerant discharge
When the air conditioning system is involved in accident damage and the circuit is punctured, the refrigerant is discharged rapidly. The rapid discharged of refrigerant will also result in the loss of most of the oil from the system. The compressor must be removed and all the remaining oil in the compressor drained and refilled as follows:
1. Gravity drain all the oil, assist by rotating the clutch plate (not the pulley).
2. Refill the compressor with the following amount of new refrigerant oil: 130 ml
3. Plug the inlet and outlet ports.
SERVICING EQUIPMENT
The following equipment is required for full servicing of the air conditioning system.
Recovery, recycling and charging station
Leak detector
Thermometer +20 °C to -60 °C
Safety goggles and gloves