A/C refrigerant system, component overview

HD = High pressure side

ND = Low pressure side

Fig 1: A/C Refrigerant System, Component Overview

Courtesy of VOLKSWAGEN UNITED STATES, INC.

1 - A/C Compressor Regulator Valve N280

• Do not remove
• Checking activation and function

2 - Compressor

• Removing refrigerant line at compressor/installing → Refrigerant lines on compressor, removing and installing 
• Replace O-rings at connections
• To protect compressor, engine is only to be started following complete assembly of refrigerant circuit
• Removing ribbed belt →
  • 13 - ENGINE - CRANKSHAFT, CYLINDER BLOCK for 1.8 LITER 4-CYL. 5V TURBO ENGINE MECHANICAL, ENGINE CODE(S): AMB
  • 13 - ENGINE - CRANKSHAFT, CYLINDER BLOCK for 2.0 LITER 4-CYL. 4V TURBO ENGINE MECHANICAL, ENGINE CODE(S): BPG, BWT
  • 13 ENGINE - CRANKSHAFT, CYLINDER BLOCK for 3.0 LITER 6-CYL. 5V ENGINE MECHANICAL, ENGINE CODE(S): AVK, BGN
  • 13 - ENGINE - CRANKSHAFT, CYLINDER BLOCK for 3.2 V6 4V ENGINE MECHANICAL, ENGINE CODE(S): BKH
  • 13 - ENGINE - CRANKSHAFT, CYLINDER BLOCK for 4.2 LITER V8 4V ENGINE MECHANICAL, ENGINE CODE(S): BNS
  • 13 - ENGINE - CRANKSHAFT, CYLINDER BLOCK for 4.2 LITER V8 5V ENGINE MECHANICAL, ENGINE CODE(S): BHF

• Removing and mounting compressor → Compressor, removing and mounting (vehicles with 4 or 6-cyl. engine) 
• Different compressors depending on country version and engine → Refrigerant system, servicing 
• On vehicles with 8-cyl. engine, the compressor is not driven via a belt, but rather by way of a shaft → Compressor drive unit, checking, replacing 
• After the installation of a new compressor or adding fresh refrigerant oil (e.g. after blowing out the refrigerant circuit), give the compressor 10 turns by hand after installing and prior to initial start-up to prevent compressor damage

3 - Oil drain plug

• "Denso" compressors are installed with a sealing ring which is always to be replaced
• Tightening torque: 30 Nm
• Compressor must be removed before screwing out to drain off refrigerant oil. Crank compressor by way of pulley or drive unit to accelerate drainage of refrigerant oil

4 - Belt pulley/compressor drive unit

• Replacing belt pulley → Belt pulley/drive unit of compressor, replacing 
• Checking and replacing compressor drive unit → Compressor drive unit, checking, replacing 

5 - Pressure relief valve, 10 Nm

• Do not remove

6 - Circuit with valve

7 - High Pressure Sensor G65

• Removing and installing → High Pressure Sensor G65, removing and installing 
• Checking signal

8 - Condenser

• Replace O-rings at connections;
• Removing and installing refrigerant lines → Refrigerant lines for condenser, removing and installing 
• Removing and installing condenser → Condenser, removing and installing 

9 - Closing cap

• With seal
• Reinstall after using service valve

10 - Service connection

• High pressure side
• For service station for measuring, discharging and recharging

11 - Bolt in refrigerant line

• Replace O-ring
• Tightening torque: 15 Nm

12 - Restrictor

• O-ring (7.5 mm/1.5 mm)
• Replace restrictor with O-ring → Refrigerant Circuit Components, Replacing
• Removing and installing → Restrictor, removing and installing 
• Lubricate O-ring slightly with refrigerant oil before installing restrictor

13 - evaporator

• Replace O-rings at connections;
• Tightening torque: Hexagon nut 25 Nm
• Removing and installing refrigerant line → Refrigerant lines on evaporator flange, removing and installing 
• Removing and installing → Heating and A/C unit, disassembling and assembling 

14 - Service connection

• Low pressure side

15 - Closing cap

• With seal
• Reinstall after using service valve

16 - Accumulator

• Replace O-rings at connections;
• Tightening torque: Socket-head bolt at block connection 25 Nm
• Removing and installing → Accumulator, removing and installing