Servicing Refrigerant Circuit

Servicing Refrigerant Circuit

• No refrigerant must be added into the refrigerant circuit discharge, evacuate and recharge refrigerant circuit.

• Compressor is always driven when engine is running; there is no magnetic clutch. Engine is therefore not to be started unless refrigerant circuit has been properly assembled. If for example the refrigerant lines are not connected to the compressor and the engine is started then the compressor may be destroyed by the build-up of internal heat. Such internal heat generation results from the fact that - even with delivery approaching 0 % - the compressor is confronted with a fixed resistance sealed circuit.

• To stop the compressor being destroyed when the refrigerant circuit is empty, it is designed such that delivery is reduced to roughly 0 % and lubrication is maintained by way of an internal oil circuit with the oil left in the compressor.

• Replacement compressors contain the full quantity of refrigerant oil required for the refrigerant circuit.

• Zexel / Valeo, Sanden and Denso compressors require different refrigerant oils.

• Different refrigerant oil capacities are designated depending on the compressor type ("6 SEU 14", "7 SEU 16" or " 7 SEU 17").

• Coat O-ring seals lightly with refrigerant oil before installing. Refer to => [ Refrigerant Circuit O-Ring Seals ] Refrigerant Circuit O-Ring Seals.

• The specified diameters for O-rings seals and the tightening torques pertain also to the threaded connections of the refrigerant lines or hoses between the separate components.

• Only install O-rings that are approved for use with refrigerant R134a.

• Check cooling performance. Refer to => [ Cooling Output, Checking ] Cooling Output, Checking.

• Check pressures in refrigerant circuit.

Work on refrigerant system should only be performed in a ventilated rooms workshops. Ensure that with in 5 meters circumference are no working-pits, basement staircases or shafts. Extraction systems are to be switched on.

Reason:

The refrigerant emerging is not only colorless and odorless, but also heavier than air and thus displaces oxygen. If refrigerant gas does escape even though all the safety precautions have been followed, there is a risk of suffocating in poorly ventilated areas and in workshop pits, even if it is not noticeable.

• The escaping refrigerant/air mixture should not be inhaled, but should be sucked out via an existing exhaust ventilation system.

Do not attempt repair on filled air conditioning systems by soldering, brazing or welding. This applies also for welding and soldering work on the vehicle, in the event that parts of the A/C system may heat up.

Reason:

Exposure to heat creates considerable pressure in the system, which could cause it to burst.

Corrective action:

Discharge refrigerant circuit. Refer to => [ Draining Refrigerant Circuit ] Draining Refrigerant Circuit.

• Damaged or leaking parts of the air conditioner are never to be repaired by welding or soldering them; they are always to be replaced.

When servicing air conditioner, all open components and pipe connections are to be immediately re-sealed.

Reason:

Moisture will ingress into air conditioner components if they are left open for a lengthy period. If this is the case, air conditioners cannot be refilled without having to replace parts of the system.