A/C Refrigerant System, Component Overview

A/C Refrigerant System, Component Overview

HD = High pressure side
ND = Low pressure side







1. A/C Compressor Regulator Valve N280
- Do not remove
- Checking activation and function

NOTE: The A/C Compressor Regulator Valve N280 is activated by the operating and display module, Climatronic Control Module J255 and controls the pressure on the low-pressure end of the refrigerant circuit.

2. Compressor
- Removing refrigerant line at compressor/installing
- Replace O-rings at connections.
- To protect compressor, engine is only to be started following complete assembly of refrigerant circuit
- Removing ribbed belt
- Removing and mounting compressor.
- Different compressors depending on country version and engine
- On vehicles with 8-cyl. engine, the compressor is not driven via a belt, but rather by way of a shaft
- 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 Refrigerant R134a - Servicing

4. Belt pulley/compressor drive unit
- Replacing belt pulley
- Checking and replacing compressor drive unit

5. Pressure relief valve, 10 Nm
- Do not remove

6. Circuit with valve

7. High Pressure Sensor G65
- Checking signal

8. Condenser
- Replace O-rings at connections.
- Removing and installing refrigerant lines

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; for version refer to Refrigerant R134a - Servicing
- 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

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