Air conditioning (Servicing precautions): Adjustments

SERVICING PRECAUTIONS

Care should be taken when handling components of the refrigeration system. 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 spanner 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 must be left in place until immediately prior to connection.

The receiver/drier contains dessicant 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 an approved refrigerant lubricating oil:

Sanden SP – 10
Unipart SP – 10

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:

Total amount of oil in system:

1.4 and 2.0 models = 135cm³
1.6 models = 120cm³

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 (Xcm³) of:

1.4 and 2.0 models = 135cm³
1.6 models = 120cm³

A calculated quantity of oil must be drained from a new compressor before fitting.

To calculate the quantity of oil to be drained:

1. Remove drain plug 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 (Ycm³).
4. Calculate the quantity (Qcm³) of oil to be drained from the NEW compressor using the following formula:

X – (Y + 20cm³) = Qcm³

Rapid refrigerant discharge

When the air conditioning system is involved in accident damage and the circuit is punctured, the refrigerant is discharge rapidly. The rapid discharge 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:

5. Remove the drain plug and gravity drain all the oil, assist by rotating the clutch plate (not the pulley).
6. Refill the compressor with the following amount of new refrigerant oil:
   1.4 and 2.0 models – 115cm³
   1.6 models – 100cm³
7. Refit the drain plug and plug the inlet and outlet ports.