General Repair Instruction, Air Conditioning System

CAUTION: Always use approved 134a recycling equipment.
- Damage to the system from leaks must be dealt with immediately to ensure that no moisture or foreign bodies get in.
- To reduce the risk of moisture in the system during repairs, it is important to keep things clean and dry at all times. Keep refrigerant compressor oil in a container with the lid on, otherwise it will absorb moisture from the air.
- When working on the A/C system, e.g. replacing components, always fit protective plugs as soon as pipe or hose connections are undone.
- When working on collision damage, for instance, it is important to check each component which could be damaged. Check welded seams with particular care. Deformed or split pipes must not be repaired.
- If there is a risk that dirt has entered a component, it must be checked and cleaned.

Absorbing Agent In Receiver/dryer:
- When repairing major leaks, replacing components or if there is a risk of moisture in the system, the dryer should be replaced. For minor leaks in favorable circumstances, there should be no need to replace the dryer more often that every third time work is performed on the system. By "favorable circumstances" we mean things such as a slow leak (over 24 hours) which is dealt with immediately.
- When replacing components (other than leaks), the dryer will not normally need replacing if the car is less than one year old or has travelled less than 20,000 km (12.500 miles). It must however be plugged within ten minutes of being opened to the air.

Topping Up Lubricating Oil:

CAUTION: Too much oil will affect cooling. Too little oil will damage the compressor.

When repairing leaks or replacing components, the lubricating oil will need topping up. The amount of oil involved for each component depends on whether the leak was fast or slow.
- Look in the engine compartment for labels indicating the refrigerant (R12 or R134a) with which the A/C system is filled. It is also important to use the correct type of oil in the system.
R12 MINERAL OIL
R134a PAG OIL
R12 to R134a (retrofit) ESTER OIL
- For more information refer to specifications for particular component or system.
- The oil must be topped up when repairing a leak or when replacing a component. The quantity required for the component in question will depend on whether leakage has taken place slowly or quickly. Rapid leakage (e.g. hose rupture) often means that lubricating oil escapes with the refrigerant. Slow leakage (longer than 24 hours) does not normally means a loss of lubricating oil.
- The following applies when replacing a compressor. Drain and measure the quantity of oil in the original compressor. Also drain the new compressor completely. The new unit should then be filled with the same quantity of oil as that drained from the original unit.

CAUTION: The compressor should always contain at least 50 ml (1.691 oz) of oil regardless of the quantity drained.

If x ml (oz) have been drained fill with x ml (oz)
70 ml (2.367 oz) 70 ml (2.367 oz)
30 ml (1.014 oz) 50 ml (1.691 oz)
50 ml (1.691 oz) 50 ml (1.691 oz)
15 ml (0.507 oz) 50 ml (1.691 oz)

- The following applies when replacing other components. Drain and measure the quantity of oil in the component which has been removed. Fill the new component with the same quantity of fresh oil prior to installation.

Slow Leaks (Longer Than 24 Hours):
Slow leaks do not normally involve a loss of lubricating oil; but, when replacing components, the following should be observed:
Compressor:
Drain oil from old compressor and measure it. Now empty the new compressor, and then fill it with the same amount of oil as was emptied from the old compressor.
Other components:
Drain and measure the amount of oil in each component removed. Add an equal amount of oil to each replacement component before fitting.

Fast Leaks (e.g. Split Hose):





Fast leaks often mean that lubricating oil has been lost along with the refrigerant. When fitting new components, they must be filled with oil as shown above.

Fitting Complete New System:
Check there is oil in the compressor (see specification). Other components must not have any oil in them.

Use Correct 0-rings (Colors) As Follow
R12 BLACK (no longer used)
R12 BLUE
R12 and R134a YELLOW