Refrigerant Circuit
Refrigerant Circuit
HD = High-pressure end
ND = Low-pressure end
1 A/C Compressor Regulator Valve (N280)
• Do not remove
• Check activation and function. Refer to => [ A/C Compressor Regulator Valve, Checking Activation Signal ] Testing and Inspection.
• The Climatronic Control Module (J255) front A/C control head activates the A/C Compressor Regulator Valve (N280). It controls the pressure on the low pressure side of the refrigerant circuit.
2 Compressor
• Removing compressor from bracket and re-installing in vehicles with 6 cylinder. 8 cylinder MPI engine or 8 cylinder diesel engine belt driven compressor. Refer to=> [ Compressor, Removing from Bracket, 6 Cylinder, 8 Cylinder MPI and 8
Cylinder Diesel ] Service and Repair
• Compressor, removing and Installing at racket, 12 Cylinder, belt driven compressor. Refer to => [ Compressor from Bracket, 12 Cylinder ] Service and Repair
• Refrigerant line, disconnecting from compressor and connecting. Refer to => [ Refrigerant Lines, Disconnecting and Connecting from Compressor ] Removal and Replacement
• To protect compressor, refrigerant circuit must have been completely assembled before starting engine
• Remove ribbed belt.
• Compressor, removing and installing. Refer to=> [ A/C Compressor ] A/C Compressor
• Compressor, removing and installing in vehicles with 8 cylinder FSI engine shaft driven compressor. Refer to=> [ Compressor, 8 Cylinder FSI ] Service and Repair
• Compressor, removing and installing, 10 Cylinder, shaft driven compressor. Refer to=> [ Compressor, S8 10 Cylinder ] Service and Repair
• The type of compressor differs depending on the engine 6, 8, 10 or 12 cylinder engine, diesel or gasoline engine.
• If a new compressor has been installed or new refrigerant oil has added to the compressor after flushing the refrigerant circuit, rotate the compressor approximately 10 rotations by hand. This prevents it from being damaged when it is activation.
• Different refrigerant oil capacities are designated depending on the compressor type ("6 SEU 14", "7 SEU 16" or " 7 SEU 17") => Refrigerant R134a - Servicing
3 Compressor belt pulley/drive unit
• Replacing compressor pulley. Refer to=> [ Compressor Pulley, Version 1 ] Service and Repair
• Ribbed belt, removing and installing.
• Replacing compressor drive unit vehicles with 8 cylinder FSI engine or 10 cylinder engine. Refer to => [ Compressor Drive Unit ] Compressor Drive Unit
4 Oil drain plug
• Denso compressors have sealing ring installed which are always to be replaced
• Tightening specification: 30 Nm
• Should only be unscrewed to drain refrigerant oil and with the compressor removed. Turn compressor via belt pulley, to speed up refrigerant oil drainage.
5 Pressure relief valve, 10 Nm
• Do not remove
6 Connection with valve
• With the refrigerant circuit empty, use an adapter from the Socket for A/C Valves (T10364) to remove and install a valve insert.
CAUTION!
The valve insert may be removed only when the refrigerant circuit is empty.
7 High Pressure Sensor for Air Conditioner (G65)
• Removing and installing, refer to => [ High Pressure Sensor ] Removal and Replacement
• Checking signal, refer to => [ High Pressure Sensor, Checking Signal ] High Pressure Sensor, Checking Signal
8 Condenser
• Refrigerant lines, disconnecting and reconnecting. Refer to => [ Refrigerant Lines, Disconnecting and Connecting from Condenser ] Removal and Replacement
• Condenser, removing and installing. Refer to => [ Condenser ] Removal and Replacement
9 Cap
• With seal
• Always to be screwed on
10 Service connection - high pressure side
• Different versions with primary sealing valve or with Schrader valve, depending on refrigerant line, distinguishing characteristics.
• To remove and install the service connection or the valve insert with the refrigerant circuit empty, use, for example, an adapter from the Socket for A/C Valves (T10364).
• For the service station for measuring pressures, emptying and charging refrigerant circuit.
• Depending on engine version, it may be necessary to remove some components in order to be able to connect to service coupling of the service station.
CAUTION!
Only remove service connections and valve inserts when the refrigerant circuit is empty. The connection does not have a valve.
11 Bolts in refrigerant line
• Replacing the o-ring seal.
• Tightening specification: 15 Nm
12 Restrictor
• installed in threaded connection => [ 11 Bolts in refrigerant line ]
• O-ring seal: 7.5 mm/1.5 mm
• Replace restrictor with O-ring
• Removing and installing, refer to => [ Restrictor ] Removal and Replacement
• Coat O-ring lightly with refrigerant oil before installing, refer to=> [ Refrigerant Circuit O-Ring Seals ] Refrigerant Circuit O-Ring Seals
13 Evaporator
• Replacing the o-ring seals.
• Removing and installing refrigerant line. Refer to=> [ Refrigerant Lines, Disconnecting and Connecting from Evaporator ] Removal and Replacement
• Removing and installing, refer to => [ Evaporator ] Removal and Replacement
14 Service connection - low pressure side
• Different versions with primary sealing valve or with Schrader valve, depending on refrigerant line, distinguishing characteristics => Air conditioning - refrigerant R134a
• To remove and install the service connection or the valve insert with the refrigerant circuit empty, use, for example, an adapter from the Socket for A/C Valves (T10364).
• For the service station to measure pressures and to discharge the refrigerant circuit.
• Depending on engine version, it may be necessary to remove some components in order to be able to connect to service coupling of the service station.
CAUTION!
Only remove service connections and valve inserts when the refrigerant circuit is empty. The connection does not have a valve.
15 Cap
• With seal
• Always to be screwed on
16 Reservoir
• Coat O-ring seals lightly with refrigerant oil before installing. Refer to => [ Refrigerant Circuit O-Ring Seals ] Refrigerant Circuit O-Ring Seals.
• Replacing the o-ring seals.
• Tightening specification: Socket hex bolt at block connection 10 Nm
• Removing and installing, refer to => [ Reservoir ] Removal and Replacement