Refrigerant Lines, Disconnecting and Connecting at Compressor
Refrigerant Lines, Disconnecting and Connecting at Compressor
• 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 running, the compressor could be destroyed by the build-up of internal heat. Such internal heat generation results from the fact that - even with delivery near 0 % - the compressor is confronted with a fixed resistance (sealed circuit).
• In vehicles with an electric engine mount, ensure the proper allocation of connectors at the engine mount and at the A/C Compressor Regulator Valve (N280), these components have the same connections. If the connectors are transposed, an error will not be stored (the components have approximately the same electric values), the engine mount will be actuated by the Climatronic Control Module (J255), and the A/C Compressor Regulator Valve (N280) by the Engine Control Module.
• The following figure shows the compressor for a vehicle with a 6 cylinder gasoline direct fuel injection engine (FSI) and 10 cyl. engine, for other engines, the position of the compressor differs slightly from this figure. The torques and additional work steps for removing and installing are essentially the same. In vehicles with an 8 or 10 cyl. engine for example, the compressor is driven with a different driveshaft, and it is installed turned 180 ° => [ Compressor, 8-Cylinder ] . The refrigerant lines are installed and removed in the same manner, regardless of their installation location.
• Seal open pipes and connections at compressor with suitable caps (to prevent ingress of dirt and moisture).
Remove the refrigerant lines
- Drain the refrigerant circuit: => A/C system - with refrigerant R134a
- If necessary, depending on the design of the motor, remove the compressor from the holder.
Additional work on vehicles with 10 cylinder engine (e.g. Audi RS6)
- Drain the coolant
- Remove the air duct hose and the hose clamps - 1 - and - 2 -.
- Remove the coolant hoses from the housing for the coolant regulator; remove hose clamps - 2 - and - 3 -.
• Disregard - item 1 - and - arrows -.
Continuation of work for all vehicles:
- Remove screws - 1 - and - 2 - (this figure shows the arrangement for a 10 cyl. engine).
- Remove refrigerant lines from A/C compressor.
CAUTION!
Risk of damaging refrigerant lines and hoses.
• Do not stretch, kink or bend refrigerant lines and hoses.
- Seal open pipes and connections on the compressor with suitable caps (to dirt and moisture from entering).
Install the refrigerant lines
Installation is carried out in the reverse order, when doing this note the following:
- Replace O-rings seals - D - and - E -.
- Check the guide ring - F - on the connections for both refrigerant lines - B - and - C - for damage.
- Insert the respective O-ring seal (- D - and - E -) in the groove - G - on the connections for both refrigerant lines - B - and - C -.
• Do not use the O-rings from the shipping caps that are installed on the connections of replacement compressor when installing lines.
• Coat O-ring seals lightly with refrigerant oil before installing => [ Refrigerant Circuit O-Ring Seals ] Refrigerant Circuit O-Ring Seals.
• Make sure the O-ring seals are seated properly in the groove - G - on the respective refrigerant line.
• Following attachment of refrigerant pipes to compressor (and installation of compressor) check routing of pipes. They must be inserted in holders provided and not make contact with other components.
- Insert both refrigerant lines - B - and - C - into each connection on the compressor.
- Tighten screws - A - with 9 Nm (screws with an M6 thread) and 25 Nm (screws with an M8 thread).
Additional work on vehicles with 10 cylinder engine (e.g. Audi RS6)
- Install the air duct hose.
Continuation of work for all vehicles:
- Install all other removed components again in reverse order.
- Evacuate refrigerant circuit and recharge again. => A/C system - with refrigerant R134a
- Fill coolant and bleed coolant circuit (e.g. for Audi RS6).
- Check the DTC memory for the Climatronic Control Module (J255) A/C control head and erase any faults displayed if necessary => Vehicle Diagnosis, Testing and Information System VAS 5051.
- Operate the A/C system after filling the refrigerant circuit => [ A/C System, Operating after Filling Refrigerant Circuit ] A/C System, Operating after Filling Refrigerant Circuit
• Note the information regarding operating the A/C system after filling => Air Conditioning with R134a refrigerant.