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:

Control and regulating unit for air conditioning system -J127
This control and regulating unit switches off the refrigerant flow through the second evaporator if the temperature at the cooling fins of the second evaporator falls to the freezing point of water (icing protection). ...

Childproof lock
Fig. 34 In the left rear door: childproof lock Ⓐ switched off, Ⓑ switched on Fig. 35 In the right rear door: childproof lock Ⓐ switched off, Ⓑ switched on First read and observe the introductory information and safety warnings The childproof lock prevents the rear doors from bein ...

Adjusting clutch engagement
The position of the engagement bearings “K 1” and “K 2” must only be adjusted after the following work: Clutch has been renewed. Engaging levers were renewed. Small ba ...