Compressor HVAC: Service and Repair
WM 873419 Removing and installing V6 air conditioning compressor
Tools
Technical values
Preliminary work
1. Draw off and dispose of refrigerant in the air-conditioning system in accordance with regulations. => 870317 Removing refrigerant by suction and filling
2. Remove engine guard. => 108019 Removing and installing engine guard - section on "Removing"
3. Release hydraulic pump at the holder and move it out of the work area together with the connected lines. => 48981900 Removing and installing hydraulic pump (Cayenne V6) - section on "Removing"
4. Remove air cleaner housing. => 242519 Removing and installing air cleaner housing - section on "Removing"
Removing air conditioning compressor
WARNING
Danger of injury. Safety regulations should be strictly observed when working on air-conditioned vehicles and dealing with refrigerant.
-> => 80 Safety regulations for working on air-conditioned vehicles and dealing with refrigerant R134a
-> => 80 Safety regulations for extraction and filling systems
-> => 80 Instructions for repairing air-conditioning systems and storing spare parts
Overview of air-conditioning compressor
1. Unscrew fastening screws -arrows 3- and pull out the two refrigerant lines -arrows-.
Removing refrigerant lines
2. Close off the connections and lines immediately using suitable plugs -b and c- , then move the lines out of the work area.
3. Release connector (for reasons of accessibility) using a suitable tool -d- ( -arrow A- ) and pull it off -arrow B-.
4. Unscrew fastening screws -1 and 2- and take out the air-conditioning compressor by moving it to the side and upwards -arrow-.
Removing air-conditioning compressor
Installing air conditioning compressor
CAUTION
Risk of damaging the air-conditioning compressor.
-> The engine must not be started until the air-conditioning system has been filled.
Information
- If the air-conditioning compressor is blocked/seized up, then additional steps must be carried out to ensure the operation of the air conditioning. => 873419 Removing and installing V6 air-conditioning compressor - section on "Information"
Information
- 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. First, open the stoppers on the high-pressure side and relieve the pressure from the compressor -b-.
Relieving pressure from compressor and opening oil filler screw
2. Open the oil filler screw -6- on the compressor.
3. Empty approx. 60 cm 3 of refrigerant oil out of the compressor and into a measuring glass. The remaining quantity of oil (approx. 80 cm3) remains in the compressor.
4. Always replace the sealing ring for the oil filler screw and tighten the oil filler screw -6-. => Tightening torque: 26 Nm (19 ftlb.)
5. Use the fastening screws from the new compressor. Replace O-rings and wet the new rings with refrigerant oil.
6. Position the bushings at the front of the compressor.
7. Place the compressor in installation position -arrow- and secure with the fastening screws -1 and 2-. => Tightening torque: 23 Nm (17 ftlb.) => Tightening torque: 45 Nm (33 ftlb.)
Installing compressor
8. Push on the connector -arrow A- until the locking lug -arrow B- engages securely.
Connecting connector and installing refrigerant lines
9. Do not remove stoppers -b and c- until shortly before installation.
10. Connect the two refrigerant lines -arrows C- and secure them with the fastening screws -arrows 3-. => Tightening torque: 20 Nm (15 ftlb.)
Information
Work steps for blocked/seized up air conditioning compressor
1. Remove desiccator from the condenser. => 875519 Removing and installing desiccator - section on "Removing"
2. Check the desiccator for wear/chips.
If there is wear/chips:
3. Remove the refrigerant line between the compressor and condenser. => 874319 Removing and installing compressor-condenser line - section on "Removing"
4. Replace the refrigerant line between the compressor and condenser.
5. Replace the condenser with desiccator. => 875019 Removing and installing condenser - section on "Installing"
6. Install the new refrigerant line between the compressor and condenser. => 874319 Removing and installing compressor-condenser line - section on "Installing"
7. => 873419 Removing and installing air conditioning compressor - V6 - section on "Installing"
If there is no wear/chips:
- Replace the desiccator. => 875519 Removing and installing desiccator - section on "Installing"
- => 873419 Removing and installing air conditioning compressor - V6 - section on "Installing"
Running-in regulations for commissioning a new air-conditioning compressor
Information
- The time specifications depend on the inertia of the temperature sensor used and can deviate from the specified times. Pay attention to the operating instructions for the temperature probe and the temperature sensor.
Information
- For the following temperature recordings, both temperature sensors must be brought to a uniform temperature level. To do this, hold both temperature sensors in front of the centre nozzle during the 4 minute idle speed phase.
1. First start (first time the engine is started on vehicle)
1.1. Switch on temperature probe and position both temperature sensors. Insert the first temperature sensor centred in the right centre nozzle approximately 4 cm deep, and position the second temperature sensor on the air inlet in the footwell on the passenger's side. Temperature probe for measuring surface and air temperature NR.164
1.2. Switch on air-conditioning compressor by pressing the ECON key (ECON goes out in display).
1.3. Set the air conditioner to maximum cooling with the temperature sensor (LO appears in the display).
1.4. Set maximum blower speed and then reduce the blower speed 3 settings to approximately 75% using the adjusting lever.
1.5. Open the right centre nozzle.
1.6. Allow engine to run at idle speed for 2 minutes.
2. Record the temperature after another 30-60 seconds.
2.1. Read out the temperature in the right centre nozzle. There must be a temperature difference of > 14 °C compared to the temperature at the air inlet in the passenger's footwell.
2.2. Switch off engine.
3. Restarting engine
3.1. Switch off air-conditioning compressor by pressing the ECON key (ECON appears in display).
3.2. Allow engine to run at idle speed for 4 minutes.
4. Start recording the temperature
4.1. Switch on temperature probe and position both temperature sensors. Insert the first temperature sensor centred in the right centre nozzle approximately 4 cm deep, and position the second temperature sensor on the air inlet in the footwell on the passenger's side. Temperature probe for measuring surface and air temperature NR.164
4.2. Switch on air-conditioning compressor by pressing the ECON key (ECON goes out in display).
Information
- With a 4 zone-air conditioner, the rear air conditioner must also be set to maximum cooling for both sides (LO) (if necessary, use the MONO function). To activate the MONO function, the AUTO -adjusting lever of the front air conditioning control must be pressed longer than 2 seconds (MONO appears in the display).
4.3. Set the air conditioner to maximum cooling with the temperature sensor (LO appears in the display).
4.4. Open the right centre nozzle.
4.5. Set maximum blower speed and then reduce the blower speed 3 settings to approximately 75% using the adjusting lever.
4.6. Hold the engine speed at a max. of 4000 rpm for 3 minutes.
5. Record the temperature after another 1-2 minutes.
5.1. Read out the temperature in the right centre nozzle. There must be a temperature difference of > 14 °C compared to the temperature at the air inlet in the passenger's footwell.
5.2. Switch off engine.
5.3. Then press the AUTO button.
Subsequent work
1. Install air cleaner housing. => 242519 Removing and installing air cleaner housing - section on "Installing"
2. Secure hydraulic pump on the holder. => 48981900 Removing and installing hydraulic pump (Cayenne V6) - section on "Installing"
3. Fill refrigerant on the air conditioner in accordance with regulations. => 870317 Removing refrigerant by suction and filling - section on "Filling"
4. After replacing the air-conditioning compressor, the running-in regulations for commissioning a new air-conditioning compressor must be carried out. => 873419 Removing and installing V6 air-conditioning compressor - section on "Information"
5. Carry out function check on air conditioning. => 80 Function check on air conditioning
6. Switch off the air conditioning again. Do not drive until the air conditioner has been filled.
7. Fit engine guard. => 108019 Removing and installing engine guard - section on "Installing"