Volkswagen Golf Service & Repair Manual: Effects on metal

Volkswagen Golf Service & Repair Manual / Air conditioning system with refrigerant R134a / General notes on air conditioning systems / Characteristics of refrigerant R134a / Effects on metal

In its pure state, refrigerant R134a is chemically stable and does not attack iron or aluminium.

However, impurities such as chlorine compounds in the refrigerant do attack certain metals and plastics. This can lead to blockages, leaks and deposits on the air conditioner compressor piston.

Critical temperature and critical pressure

Up to a gas pressure of 39.5 bar positive pressure (corresponding to a temperature of 101°C) the refrigerant R134a remains chemically stable; however, above this temperature the refrigerant decomposes (see Combustibility).

Vapour pressure

In an enclosed container that is not completely full, refrigerant evaporates as vapour at the surface in a quantity sufficient to form an equilibrium between vapour a ...

Water content

Only very small amounts of water are soluble in liquid refrigerant. On the other hand, refrigerant vapour and water vapour mix in any proportion. ...

Other materials:

Assembly overview - steering wheel
1 - Steering column Removing and installing → Chapter The centre punch marks -arrows- on the steering wheel and the steering column must align when reinstalling. Some steering columns leave the factory with no centre ...

Removing and installing rain and light sensor, vehicles without front camera for driver assist systems
Note The rain and light sensor has a silicon layer (coupling pad) which forms the contact surface to the windscreen. The rain and light sensor has been designed so that it can be used again. A prerequisite for re-use ...

Removing and installing control unit for daytime running light and side light -J860-/-J861-
WARNING Risk of death due to high voltage! Risk of injury and environmental pollution! Observe operation and safety notes for gas discharge bulbs → Chapte ...