Procedures
873419 Removing And Installing Air-Conditioning Compressor
Preliminary work
Preliminary work for air-conditioning compressor
1. Drain refrigerant for air-conditioning system with a refrigerant pump.
2. Remove drive belt.
General warning notes
General warning notes for air-conditioning compressor
WARNING:
Safety regulations should be strictly observed when working on air-conditioned vehicles and dealing with refrigerant.
- Danger of injury.
- Safety regulations for working on air-conditioned vehicles and handling refrigerant
- Safety regulations for extraction and filling systems.
- Instructions for repairing air-conditioning systems and storing spare parts.
Tools and materials
Tools for air-conditioning compressor
Air-conditioning service unit, refer to Special Tools, Commercially Available Tools, Chapter 2.4, No. 96-2.
Removing air-conditioning compressor
1. Take out the connector for the compressor from between the intake pipes and pull apart.
2. Remove the three fastening screws -1- from the air conditioning compressor. The rear screw can only be pulled out after removal.
3. Lift the air-conditioning compressor with the rear fastening screw and pull out of the engine.
4. Place the air-conditioning compressor with the lines on the rear support plate and remove the two fastening screws -1, 2-.
5. Immediately close off connections and lines with suitable plugs.
Installing air-conditioning compressor
ATTENTION:
Risk of damaging the air-conditioning compressor.
- The engine must not be started until the air-conditioning system has been filled.
NOTE:
- New compressors are pressurised and are filled with the required amount of oil for the refrigerant circuit.
- The remaining oil quantity in the individual components must therefore be taken into account.
- Refrigerant oil from the compressor or refrigerant oil removed by suction from a previously run air-conditioning system may no longer be used (special-category waste).
1. If a new compressor is installed, first correct the refrigerant oil quantity in the air-conditioning compressor.
2. Replace O-rings for the refrigerant lines and wet the new rings with refrigerant oil.
3. Do not remove the plugs for the lines and compressor connection until shortly before installation.
4. Connect the lines and secure with the fastening screws -1, 2-. M8 15 ftlb M8 15 ftlb.
5. Insert the rear fastening screw into the air-conditioning compressor.
6. Place the air-conditioning compressor with the rear fastening screw on the engine housing and screw down with the three fastening screws -1-. M8 17 ftlb.
7. Connect the plug and place between the pipes of the intake system.
Subsequent work
Subsequent work for the air-conditioning compressor
Install drive belt.
Fill refrigerant on the air-conditioning system in accordance with regulations.
Open air outlet nozzles on the instrument panel, and set blower to at least 75 %.
After allowing the system to stabilise at idle speed (approx. 5 sec), switch on air conditioning and allow the engine to run uninterrupted for at least 2 minutes at 1500 rpm.
Switch off the air-conditioning system again. Do not drive until the air-conditioning system has been filled.
Checking refrigerant oil in "new" air-conditioning compressor
Correct the refrigerant oil level in the "new" air-conditioning compressor
WARNING:
A new air-conditioning compressor contains the oil quantity for the complete air-conditioning circuit.
- Risk of damaging the air-conditioning compressor by excessive refrigerant oil in the air-conditioning circuit.
- If a new air-conditioning compressor or a component in the circuit is replaced, the oil quantity must be determined and adjusted.
- Insufficient refrigerant oil causes a lack of lubrication, resulting in the failure of the air-conditioning compressor.
- Too much refrigerant oil results in reduced refrigerant performance.
NOTE:
- All connection points must be completely dirt-free.
- The air-conditioning compressor must be dry (washing the vehicle) and the air-conditioning compressor and lines must be free of moisture.
- The connection points must be closed after they have been opened. Use the original transport caps.
- A clean measuring cylinder with a capacity of approx. 300 ml is required.
Determining oil quantity on the "old" air-conditioning compressor
1. First, open the cap on the high-pressure side and relieve the pressure from the compressor -A-.
2. Open the oil filler screw -B- on the compressor.
3. Fill the refrigerant oil from the air-conditioning compressor into the measuring cylinder. Turn the pressure plate on the air-conditioning compressor (not the belt pulley) when emptying the refrigerant oil.
The amount of refrigerant oil is referred to as "V(old)" in the formula below:
4. Always replace the sealing ring for the oil filler plug.
5. Screw oil filler plug -B- into the compressor. M8 22 ftlb.
Determining the oil quantity at the "new" oil filler screw of the air-conditioning compressor
1. To drain refrigerant oil:
1.1 First, open the cap on the high-pressure side and relieve the pressure from the compressor -A-.
1.2 Open the oil filler screw -B- on the compressor.
1.3 Drain the refrigerant oil from the air-conditioning compressor. The refrigerant oil must not be re-used, but must be disposed of properly.
2. To determine the refrigerant oil quantity:
2.1 V(total) = "V(removed)" + "V(old)" + 20 cubic cm
2.2 V(total) = Total volume for the new air-conditioning compressor
2.3 V(removed) = Volume of refrigerant oil removed by suction
2.4 V(old) = Volume of refrigerant oil in the old air-conditioning compressor
2.5 20 cubic cm = Additional safety volume
3. To fill the air-conditioning compressor:
3.1 Fill the determined refrigerant oil volume V(total) into the air-conditioning compressor.
3.2 Always replace the sealing ring for the oil filler plug.
3.3 Screw oil filler plug -B- into the compressor. M8 22 ftlb.
3.4 Install air conditioning compressor.