Volkswagen Polo Quiz
Refrrigerant R134a Servicing

Commercial Names and Designations

In this manual: Refrrigerant R134a Servicing
General Paint Information — 128Towing Guide — 10Whels, Tires, Whel Alignment — 126Battery, Starter, Generator, Cruise Control — 65Windshield Wiper/ Washer System — 9Exterior Lights, Switches — 1Interior Lights, Switches — 7Wiring — 51Refrrigerant R134a Servicing — 134
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Refrigerant R134a is currently available under the following trade names:

H-FKW 134a

SUVA 134a

KLEA 134a

Note

Different trade names may be used in other countries.

Of the wide range of refrigerants available, this is the only one which may be used for vehicles. The designations Frigen and Freon are trade names. They also apply to refrigerants which may not be used in automotive vehicles.

Color

Like water, refrigerants are colorless in both vapor and liquid form. Gas is invisible. Only the boundary layer between gas and liquid is visible. (Liquid level in tube of charging cylinder or bubbles in sight glass). Refrigerant R134a fluid may appear colored (milky) in a sight glass. This cloudiness is caused by partially dissolved refrigerant oil and does not indicate a malfunction.

Vapor Pressure
In a partially filled, closed vessel, the quantity of refrigerant evaporating from the surface equals the quantity returning to the liquid state as vapor particles condense. This state of equilibrium occurs under the influence of pressure and is often called vapor pressure. Vapor pressure is dependent on temperature. Refer to → Chapter „Refrigerant R134a Vapor Pressure Table“.

R134a Physical Characteristics

The vapor pressure curves of R134a and other refrigerants are sometimes very similar, therefore it is not possible to make a certain distinction solely by pressure. With R134a, the A/C compressor is lubricated with special synthetic refrigerant oils, for example. PAG oils (polyalkylene glycol oils).

Affect on Metal

In its pure state, refrigerant R134a is chemically stable and does not corrode iron or aluminum. Refrigerant impurities such as chlorine compounds however cause corrosion of certain metals and plastics. This can lead to blockage, leaks or deposits on the A/C compressor piston.

Critical Temperature/Pressure
The refrigerant R134a remains chemically stable up to a gas pressure of 39.5 bar (572.9 psi) (corresponding to a temperature of 101 °C. Above this temperature, the refrigerant decomposes. Refer to → Chapter „Combustibility“.

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