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:

Removing and installing glove compartment light -W6-
Removing – Turn light switch to “0” position. – Press in locking lug -1- using a flat screwdriver, and lever out glove compartment light -2-. ...

Removing and installing humidity sender for air conditioning system -G260-
The humidity sender for air conditioning system -G260- and the light/rain sensor -G397- form one component and are installed depending on vehicle equipment. – Removal and installation procedure is described in → E ...

Seam seals, body of CNG-powered vehicles
Note Seam seals made during repair work must be identical in appearance and thickness to the original seam seals. To avoid damage or faulty operation, brush seam seals smooth near attachments which must be attached. ...