Volkswagen Golf / Golf GTI / Jetta. Manual — part 1000

The expansion valve atomizes the streaming refrigerant
and controls the flow quantity so that the vapor is gaseous
only at the evaporator outlet, depending on the heat
transmission.

O-ring seals

These rings seal off the connection points between
individual components of the refrigerant circuit.

Only O-rings that are resistant to refrigerant R134a and
refrigerant oil must be installed. Make sure they are original
replacement parts.

Parts Catalog

O-ring seals:

- Always use only once.

- Make sure diameters - a - and - b - are correct.

- Lubricate with refrigerant oil before installing.

Note:

- The color coding of O-rings for the R134a refrigerant
circuits has been discontinued. Colored and black O-rings
are used.

Repair Manual, Heating & Air Conditioning, Repair

Group 87 ,

Parts Catalog

Refrigerant circuit pipes and hoses

The mixture of refrigerant oil and refrigerant R134a
corrodes certain metals (e.g. copper) and alloys and
dissolves some hose materials. Therefore use original
replacement parts only.

Pipes and hoses are joined together by threaded
connections or via special plug connectors.

Note:

General information on refrigerant circuit

13/2/2005

- Observe specified torques for threaded connections, use
appropriate release tools for plug connectors.

Pressure relief valve

Pressure relief valve is installed on A/C compressor or
receiver.

At a pressure of approx. 38 bar positive pressure, valve
opens and closes again once pressure has dissipated
(approx. 30 bar).

Refrigerant does not escape completely.

Depending on the version, a transparent plastic disc may
be installed which breaks off as soon as the valve is
activated.

Design of refrigerant circuit

Refrigerant circuit with expansion valve and
evaporator

1. Evaporator
2. Expansion valve
3. Valve for extracting, filling and measuring
4. Receiver with desiccant bag / dryer cartridge
5. Condenser
6. A/C compressor

Note:

- Arrows point in direction of refrigerant flow.

Refrigerant circuit with restrictor and reservoir

General information on refrigerant circuit

13/2/2005

1. A/C compressor
2. Condenser
3. Restrictor
4. Evaporator
5. Reservoir with desiccant bag

Note:

- Arrows point in direction of refrigerant flow.

Connections for quick-release coupling on
refrigerant circuit

Warning!

There is a danger of ice-up.

Refrigerant may leak out if refrigerant circuit is not
discharged.

Refrigerant must be extracted before opening
refrigerant circuit.

- Only valves and connections that are resistant to
refrigerant R134a and refrigerant oil must be installed.

- Different connections (outer diameter) for high pressure
and low pressure side.

- Always screw on sealing caps.

Arrangement in vehicle.

Repair Manual, Heating & Air Conditioning, Repair

Group 87 ,

Extraction and filling valve with Schrader valve

A - Service connection (soldered in)

B - Schrader valve insert

C - O-ring seal (belongs to valve)

D - Sealing cap with seal

General information on refrigerant circuit

13/2/2005

Evacuating and charging valve, high pressure
side

1. Socket with external and internal threads
2. O-ring: 10.8 mm; 1.8 mm identification: black or

colored

3. Evacuating and charging valve with groove for O-ring

and external or internal thread M 8x1 for cap

4. O-ring for cap, 10.8 mm; 1.8 mm identification: black

or colored

5. Cap

Evacuating and charging valve, low pressure
side

1. Socket with external thread and groove for O-ring
2. O-ring: 7.6 mm; 1.8 mm identification: black or

colored

3. Evacuating and charging valve internal thread for cap

M 8x1

4. O-ring for cap, 7.6 mm; 1.8 mm identification: black or

colored

5. Cap

Switches and sensors on refrigerant circuit
and corresponding connections

General information on refrigerant circuit

13/2/2005