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:

Front brakes
The type of brake system installed in the vehicle is indicated among other things by the corresponding PR number on the vehicle data sticker. The vehicle data sticker can be found in the spare wheel well and in the service schedule. ...

Removing and installing turn signal bulb
Note Removal and installation are described for the left side. Removal and installation on the right side are carried out in the same way. Removing – Remove tail light cluster on body & ...

Nuts and bolts
Loosen and tighten bolts and securing nuts for covers and housings diagonally. Avoid canting particularly sensitive parts such as comtrol motor with control unit. Loosen and tighten them diagonally in stages. ...