Volkswagen Golf Service & Repair Manual: Checking

Volkswagen Golf Service & Repair Manual / Air conditioning system with refrigerant R134a / Checking pressures on vehicles / Checking systems with an expansion valve and reservoir (without regulated air conditioner compressor) / Checking

Switch off ignition.

–	Connect manifold gauge (air conditioner service station).

–	Read pressure gauge. It may display two results, A and B.

Ambient temperature in degrees centigrade	Pressure in the refrigerant circuit in bar positive pressure
+15°C	3.9
+20°C	4.7
+30°C	6.7
+40°C	9.1

A- The pressure in the refrigerant circuit is less than shown in the table, (insufficient refrigerant in the circuit).

- Check for leaks using leak detector.

- The high-pressure safety valve has opened; check the activation for the radiator fan referring to the current flow diagram.

Check refrigerant pipes and refrigerant hoses for bends that have too tight radius (restrictions in cross-section) and for external damage. If no faults are found, purge the refrigerant circuit.

B- The pressure in the refrigerant circuit is greater than or equal to the value in the table.

–	Start engine.

–	Set air conditioning system to maximum cooling power.

–	Open doors.

–	Open vents in dash panel.

The air conditioner compressor is driven by the engine, via the V-belt and magnetic clutch.

Note

If the air conditioner compressor is not being driven, check the power supply for the air conditioning system magnetic clutch -N25- in accordance with the current flow diagram.

If power supply is OK, repair magnetic clutch.

If the air conditioner compressor is not being driven, check the refrigerant circuit:

–	Raise engine speed to 2,000 rpm.

–	Observe the manifold gauge.

Specifications

High-pressure side:

Increasing from the pressure when the engine is stopped to a maximum of 20 bar positive pressure.

Low-pressure side:

Decreasing from the pressure when the engine is stopped to 1.3 bar positive pressure.

Test prerequisites

Radiator and condenser must be clean (clean them if necessary). The V-belt for air conditioner compressor and alternator is correct ...

Checking systems with a restrictor and reservoir and air conditioner compressor regulating valve -N280- (with externally regulated air conditioner compressor)

Note Connecting air conditioner service station → Chapter. Observe the test prerequisites → Cha ...

Other materials:

Repairing smooth pipe
Smooth pipe with a diameter or 5x1 mm or 6x1 mm can be repaired with EPDM hose. – Cut damaged section at right angles out of smooth pipe which is to be repaired. – Select the appropr ...

Assembly overview - window regulator
1 - Front door 2 - Hexagon nut Qty. 5 6 Nm 3 - Window regulator Removing and installing → Chapter. 4 - Bolt Qty. 3 3 Nm 5&n ...

Renewing rear bonded rubber bush for lower suspension link
Special tools and workshop equipment required Tube for wheel bearing -3345- Assembly tool -3348- Thrust plate -VW 401- Press tool -VW 411- Press tool -VW 412- Removing and installing to ...