873419 Removing and installing air conditioning compressor
WM 873419 Removing and installing air conditioning compressor
Tools
Technical values
Preliminary work
Preliminary work for air-conditioning compressor
1. Drain refrigerant for air-conditioning system using a refrigerant pump.
2. Remove drive belt. => Removing and installing drive belt - section on "Removing".
3. Remove intake-air distributor. => 24461900 Removing and installing intake-air distributor - section on "Removing"
General warning notes
General warning notes for air-conditioning compressor
WARNING
Refrigerant
- Danger of freezing
-> Avoid contact with refrigerant.
-> Wear personal protective gear.
-> Observe the safety regulations for working on air-conditioned vehicles and dealing with refrigerant.
-> Observe the safety regulations for extraction and filling systems.
-> Observe the 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)
Removing air conditioning compressor
1. Cut tie-wrap for the electric plug connection and pull the electric connector -2- apart.
Disconnecting plug connection for compressor
2. Unscrew the fastening screws -1, 2- for the air-conditioning lines on the compressor and at the engine compartment connection point.
Unscrewing fastening screws for air-conditioning lines, shown on the 911 Turbo
3. Unscrew the three fastening screws -4- on the air-conditioning compressor.
Unscrewing fastening screws on the air-conditioning compressor
4. Unscrew the fastening screws -5- on the air-conditioning compressor and remove the air-conditioning lines.
Removing air-conditioning lines on the compressor
5. Close off air-conditioning lines and the compressor with commercially available plugs.
Installing air conditioning compressor
1. Remove plugs used to close off the compressor and refrigerant lines.
2. Moisten the seals of the two refrigerant lines with refrigerant oil, slide them into the air-conditioning compressor and secure in place with the two fastening screws -5-.=> Tightening torque: 23 Nm (17 ftlb.)
Fitting refrigerant lines on air-conditioning compressor
3. Moisten the seals for the two refrigerant lines with refrigerant oil. Fit the refrigerant lines on the compressor and on the engine-compartment connection point and secure in place with the two fastening screws -1, 2-.=> Tightening torque: 23 Nm (17 ftlb.)
Fitting air-conditioning lines, shown on the 911 Turbo
4. Position the air-conditioning compressor on the engine and secure to the engine with the three fastening screws -4-. => Tightening torque: 23 Nm (17 ftlb.)
Securing air-conditioning compressor
5. Route electric line and connect the plug connection -2-.
Connecting plug connection for compressor
6. Fix the electric line in place on the reservoir bracket using a tie-wrap.
Subsequent work
Subsequent work for the air-conditioning compressor
1. Install intake-air distributor. => 24461900 Removing and installing intake-air distributor - section on "Installing"
2. Fit drive belt. => 137819 Removing and installing drive belt - section on "Installing"
3. Fill the air-conditioning system with refrigerant in accordance with regulations. => 870317 Draining and filling in refrigerant
4. Open air exhaust nozzles on the dashboard and set fan to at least 75 %.
5. After allowing the system to stabilise at idle speed (approx. 5 sec.), switch on air conditioning and allow the engine to run uninterrupted at 1500 rpm for at least 2 minutes.
6. Switch off the air conditioning 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
NOTICE
Too much or too little refrigerant oil in air conditioning circuit
- Reduced cooling output
- Lack of lubrication and failure of the air conditioning compressor
-> If a new air conditioning compressor or a component in the circuit is replaced, the oil quantity must be checked and adjusted.
Information
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-.
Caps
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 "Vold" in the formula below.
4. Always replace the sealing ring for the oil filler plug.
5. Screw oil filler plug -B- into the compressor. => Tightening torque: 30 Nm (22 ftlb.)
Determining oil quantity on the "new" air conditioning compressor
Oil filler screw
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" + "Vold" + 20 cm3
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. Vold = Volume of refrigerant oil in the old air conditioning compressor
2.5. 20 cm3 = 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- onto the compressor. => Tightening torque: 30 Nm (22 ftlb.)
3.4. Install air conditioning compressor. => 873419 Removing and installing compressor - Installing
Work steps for blocked/seized up air conditioning compressor
1. Remove desiccator. => 875519 Removing and installing desiccator - section on "Removing"
2. Check the connections at both condensers, at the desiccator and at the refrigerant lines for the desiccator for any wear/chips.
If there is wear/chips:
3. Unscrew the refrigerant line between the compressor and condenser at the connection points on the compressor and on the condenser and disconnect it. => 874319 Removing and installing compressor/condenser line - section on "Removing"
WARNING
Toxic substances
- Danger of poisoning or suffocation
-> Ventilate the work area well.
-> Never ingest or inhale.
-> Read specific information on the Hazard Sheet.
-> Wear personal protective gear.
4. Rinse out the refrigerant line between the compressor and condenser using commercially available acetone, for example. The acetone dissolves the refrigerant oil ND 8 in the air-conditioning line.
A suction and pressure syringe can be used to rinse out the refrigerant line.
Suction and pressure syringe Nr.194
4.1. Allow the acetone in the refrigerant line to dry off.
WARNING
Working with compressed air
- Risk of eye injuries
- Risk of damaging and dirtying components
-> Wear protective goggles with side eye protection.
-> Protect the point at which the compressed air emerges with suitable material.
-> Place the point at which the compressed air emerges on suitable surfaces.
5. Wrap a light-coloured material several times around the refrigerant line connection for the condenser and secure the material on the line with a tie-wrap. Make sure that the compressed air can escape through the cloth. Any wear fragments must remain in the cloth.
6. Blow pure compressed air (no oil or water impurities permitted) through the refrigerant line between the compressor and condenser.
7. Replace both condensers and the desiccator. => 875019 Removing and installing condenser;-=> 875519 Removing and installing desiccator - section on "Removing"
8. Reinstall the refrigerant line between the compressor and condenser at the compressor and at the condenser. => 874319 Removing and installing compressor-condenser line - section on "Installing"
9. Replace air conditioning compressor. => 873419 Removing and installing air-conditioning compressor - "Installing" section
If there is no wear/chips:
10. Replace the desiccator. => 875519 Removing and installing desiccator
11. Replace air conditioning compressor. => 873419 Removing and installing air-conditioning compressor - "Installing" section