Servicing
HD = high pressure side
ND = low pressure side
NOTES:
- Starting September 1998, there was a running change in production from the version 1 air conditioner to the version 2 air conditioner. Application and ID
- Always observe safety measures. Service Precautions
- A/C system components identified with an asterisk (*) may only be serviced or replaced after properly discharging refrigerant system.
- A/C system components not identified with an asterisk (*) can be serviced or replaced without discharging refrigerant system.
- Compressors supplied as replacement parts already contain the full quantity of refrigerant oil required for the A/C system (250 cubic cm)
- A/C system cooling performance test. Testing and Inspection
- Do not add refrigerant to the A/C system. Always discharge, evacuate and recharge system.
- The tightening torques and O-ring diameters given also apply to the threaded connections for the refrigerant lines between components.
- Install only O-rings that are approved for use with refrigerant R134a (currently color-coded red, light purple and dark purple). See parts catalog microfiche or contact your Audi dealer parts department.
- Checking pressures in the A/C system. Testing and Inspection
1 - Compressor (Denso) *
- Removing and installing ribbed belt. Drive Belt
For the following procedures, Service and Repair
- Removing and installing compressor and/or compressor bracket.
- Detaching refrigerant lines from Denso compressor, O-ring specifications and tightening torques.
- Removing from bracket (8-cylinder).
CAUTION!
- If a new compressor has been installed or new refrigerant oil has been put into the compressor (e.g. after blowing through the A/C system and discharging the compressor via the oil drain plug), the compressor must be turned manually approx. 10 revolutions. This ensures that the compressor is not damaged when activated.
- Mark the running direction of the ribbed belt before removing. The belt could break if allowed to run in the reverse direction.
NOTES:
- All 6-cylinder engines are installed with Denso compressors.
- The compressor has a variable piston stroke which adjusts itself according to the cooling level required.
2 - A/C clutch -N25-
- Servicing, Checking and adjusting gap between pulley and clutch plate Service and Repair
3 - Oil drain plug *
- Tightening torque: 30 Nm (22 ft. lb)
NOTES:
- The Denso compressor drain plug is installed with an ordinary sealing ring instead of an O-ring. This must always be replaced.
- Only remove the plug to drain the refrigerant oil.
4 - Pressure relief valve *
- O-ring: 8.8 mm x 1.9 mm
- Tightening torque: 10 Nm (7 ft. lb)
CAUTION! Connection -5- does not have a Schrader valve to prevent gas from escaping if the pressure relief valve is removed. Only remove the pressure relief valve when the refrigerant has been discharged from the A/C system.
5 - Connection with valve *
6 - A/C pressure switch -F129-
7 - Condenser *
- Removing and installing condensor or refrigerant lines for condenser with block connection Service and Repair
- Different refrigerant R-134a capacities depending on condenser type. Capacity Specifications
8 - Coupling in refrigerant line *.
- O-ring: 10.8 mm x 1.8 mm
- Tightening torque: 15 Nm (11 ft. lb)
9 - Cap
- With seal
- A ways re-install after using service valve
10 - Service valve *
- High pressure side
- For measuring, discharging and recharging
11 - Restrictor *
- Always replace restrictor (together with O-ring)
- Installed in coupling -8-
- O-ring: 7.5 mm x 1.5 mm
- Removing and installing Service and Repair
12 - Evaporator *
- Disconnecting and connecting refrigerant lines.
- Removing and installing / disassembling and assembling air conditioner unit Service and Repair
Two different versions:
- Version 2: width of evaporator is 32 mm less than in version 1
- Version 1: evaporator can only be replaced together with air distributor housing
13 - Service valve *
- Low pressure side
14 - Cap
- With seal
- Always re-install after using service valve
15 - Accumulator *
- Removing and installing Service and Repair