Volkswagen Golf / Golf GTI / Jetta. Manual — part 966

87-81

Receiver drier

The receiver drier acts as a
refrigerant reservoir for the system.
Any moisture in the system forms as
droplets and is absorbed in the drier
desiccant.

Note:

To ensure optimum system
operation, replace receiver drier
every time refrigerant system is
opened.

CAUTION!

The receiver drier may be
identified with a label that
indicates the drier desiccant
inside is only compatible with R-
134a refrigerant. NEVER use an R-
12 receiver drier in and R-134a
system.

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Expansion valve

The expansion valve restricts and
controls refrigerant flow to the
evaporator thus lowering refrigerant
temperature and pressure.

Note:

The R-134a expansion valve may be
identified as such with a label.

Evaporator

Liquid refrigerant entering the
evaporator absorbs heat from air
passing through the evaporator fins
and cools the air. As the refrigerant
absorbs heat it turns to vapor and
then is suctioned by the
compressor.

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O-rings

O-rings seal connections between
A/C system components.

Notes:

Always use correct size O-rings

(dimensions -a- and -b-).

Do not reuse O-rings, always

replace. Use only new O-rings
that are compatible with R-134a
refrigerant and refrigerant (PAG)
oil on R-134a systems.

O-rings for use only on R-134a

systems may be red, green,
violet or black.

Lubricate O-rings with the

appropriate refrigerant oil before
installing (only use PAG oil).

Pressure relief valve

The pressure relief valve is mounted
on the compressor or compressor
inlet/outlet manifold. At pressures
above 40 bar (580 psi), the pressure
relief valve opens to air outlet
excessive pressure. When the
system pressure is reduced, the
valve closes to prevent total
refrigerant loss.

An adhesive cap on the end of the
pressure relief valve pops out when
the valve has opened.

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A/C pressure switch -F129-

-F129- has three functions:

Notes:

Switches the A/C clutch -N25- off

when excessive refrigerant circuit
pressure is present (e.g.:
insufficient air flow over
condensor or when
overcharged).

Switches the A/C clutch -N25- off

when insufficient refrigerant
circuit pressure is present (e.g.:
when refrigerant has leaked out)

Switches on the second speed

coolant fan -V7- when refrigerant
circuit pressure increases.

The presence of -F129- is engine

dependant. Where -F129- is not
used, high pressure sensor -
G65- is used instead

Page 87-

85

.

Always confirm system use of

either -F129- or -G65- and
applicable wiring circuit using
applicable "Engine" and "Air
conditioning" wiring diagrams.

A/C refrigerant system

13/2/2005