Porsche P-80 2005, Руководство пользователя

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Climate Control Systems Diagnosis & Repair
Air Conditioning Basics
Lines and Hoses
A/C system components are connected by rigid lines and
flexible hoses. This creates the closed loop through which
the refrigerant flows. Rigid lines are formed aluminum. The
flexible hoses are a reinforced rubber compound with a
barrier liner.
Low pressure lines and hoses are generally larger in
diameter when compared with high pressure lines and
hoses. This is because refrigerant gas in the low side has
expanded and takes up much more space than either
refrigerant gas or liquid on the high side.
Joints may be several types but always have o-rings for
sealing. When assembling lines or replacing o-ring seals,
always lubricate o-rings only with PAG oil. The oil helps the
o-ring to properly seat and seal. Do not use any other
lubricant. Always torque fasteners to specifications.
Service Connections
911 Carrera (993) models have A/C high and low side
service connections located in the rear near the A/C
compressor.
911 Carrera (996)/(997) and Boxster (986)/(987) model connec-
tions are located in the cowl area on the right side, near the
battery and expansion valve.
Cayenne model service connections are in front in the engine
compartment on the left side.
R-134a service connection fittings are quick-connect style
and are different from those on R-12 systems. This was
done to prevent cross-contamination of refrigerants which
cannot be mixed. R-134a quick connect fittings are
different sizes for the high and low sides. This ensures
that the low side and high side service hoses are properly
connected to their respective ports. Disconnecting an R-
134a service hose quick-connector automatically seals the
ports to retain the refrigerant in the vehicle’s system and
also in the service hose.
R-12 systems use threaded service connection fittings and
hand shut-off valves. By law, the shut-off valves must be no
more than 30 cm (12 in.) from the end of the service hose
to reduce refrigerant loss.