Volkswagen Golf / Golf GTI / Jetta. Manual — part 964

87-73

CAUTION!

- Immediately plug open connections on
A/C components to prevent dirt and
moisture contamination. Likewise, DO NOT
remove new components from packaging
until ready to install. Immediately tighten
component connections after installation

- Always use separate refrigerant
recovery/recycling/recharging servicing
equipment for R-12 and R-134a systems.
DO NOT use one piece of equipment for
both R-12 and R-134a systems. The
residual traces of refrigerant will
contaminate and damage the equipment.
Servicing equipment includes
recovery/recycling/recharging unit,
charging station, vacuum pump, manifold
gauges, etc.

- DO NOT use R-12 servicing equipment on
R-134a systems or R-134a equipment on
R-12 systems or damage to both the
vehicle A/C system and servicing
equipment may result. Use only equipment
designed to meet Society of Automotive
Engineers (SAE) standards

- R-134a and R-12 systems use different
size service fittings. NEVER use adaptors
to convert an R-12 fitting to R-134a size or
R-134a fitting to R-12 size

- R-134a and R-12 A/C components
including compressor, hoses, O-rings,
evaporator, condenser, receiver-drier, etc.
are NOT interchangeable. Components of
the R-134a system are identified by
lettering (R-134a) or by a green label (or
stripe). In addition a label on the upper
radiator support identifies which type
refrigerant is used. Use only the correct
system component for each refrigerant
type

A/C refrigerant system

13/2/2005

87-74

CAUTION!

- Always replace damaged and/or leaking
A/C system components. Do not attempt
repair by soldering or welding

- Work area must be extremely clean
when working on A/C system
components

discharge A/C system before removing
any A/C system component

- Always reinstall caps over A/C service
valves

- Always replace O-rings, DO NOT reuse.
Use only the correct size and type of O-
rings specified for use with R-134a
refrigerant. Lubricate O-ring with
refrigerant oil before installing

A/C refrigerant system

13/2/2005

87-75

A/C refrigerant R-134a, properties

Commercial designation

The following designations are used and

appear on component labels and factor
tags:

R-134a

Tetrafluoroethane

CH

2

F CF

3

H-KW 134a

SUVA

134a

ARCTON

134a

Color

Refrigerant R-134a is colorless and is

invisible as a gas. R-134a when viewed
through the sight glass may appear milky
due to the mixture of refrigerant and
lubricating oil (PAG oil).

Page 87-69

A/C refrigerant system

13/2/2005

87-76

Temperature/pressure relationship

R-134a in an enclosed container will have a

specific temperature/pressure relationship.

Temperature in C ( F) Pressure in bar (psi)

-30 (-22)

0.0 (0.0)

-20 (-4)

0.3 (4.4)

-10 (14)

1.0 (14.5)

0 (32)

1.9 (27.5)

10 (50)

3.1 (45.0)

20 (68)

4.7 (68.2)

30 (86)

6.7 (97.2)

40 (104)

9.1 (132.0)

50 (122)

12.2 (177.0)

60 (140)

15.8 (229.2)

70 (158)

20.2 (293.0)

Refrigerant oil

A special Polyalkylene Glycol (PAG)

synthetic oil is used in R-134a systems. This
oil is NOT compatible with mineral based oils
used in R-12 systems. See safety measures

Page 87-69

for Warnings and Cautions

regarding proper oil usage.

A/C refrigerant system

13/2/2005