Discovery II
GENERAL INFORMATION
03-25
Service precautions
Observe the following precautions when handling
components used in the air conditioning system:
l
Air conditioning units must not be lifted by their
hoses, pipes or capillary lines.
l
Hoses and lines must not be subjected to any
twist or stress; the efficiency of the system will
be impaired by kinks or restrictions. Ensure that
hoses are correctly positioned before tightening
couplings, and ensure that all clips and supports
are utilised.
l
Flexible hoses should not be positioned close to
the exhaust manifold (less than 100mm) unless
protected by heat shielding.
l
Completed assemblies must be checked for
refrigeration lines touching metal panels. Any
direct contact of components and panels may
transmit noise and so must be eliminated.
l
The appropriate torque wrench must be used
when tightening refrigerant connections to the
stipulated value. An additional spanner must be
used to hold the union to prevent twisting of the
pipe when tightening connections.
l
Before connecting any hose or pipe, ensure that
refrigerant oil is applied to the seat of the new 'O'
rings, BUT NOT to the threads of the
connection.
l
All protective plugs must remain in place to seal
the component until immediately prior to
connection.
l
Ensure components are at room temperature
before uncapping, to prevent condensation of
moisture from the air that enters it.
l
Components must not remain uncapped for
longer than 15 minutes. In the event of a delay,
the caps must be fitted.
l
When disconnecting, immediately cap all air
conditioning pipes to prevent ingress of dirt and
moisture into the system.
l
The receiver/drier contains desiccant which
absorbs moisture. It must be positively sealed at
all times. A receiver/drier that has been left
uncapped must not be used, fit a new unit.
l
The receiver/drier should be the last component
connected to the system to ensure optimum
dehydration and maximum moisture protection
of the system.
l
Whenever the refrigerant system is opened, the
receiver/drier must be renewed immediately
before evacuating and recharging the system.
l
Use alcohol and a clean lint-free cloth to clean
dirty connections.
l
Ensure that all new parts fitted are marked for
use with R134a.
When a major repair has been completed, a leak test
should be conducted; refer to the Air Conditioning
section of this manual for the correct procedure.
Refrigerant oil
Refrigerant oil easily absorbs water and must not
be stored for long periods. Do not pour unused
refrigerant oil back into the container. Always
use an approved refrigerant oil.
CAPACITIES, FLUIDS, LUBRICANTS
When replacing components in the A/C system,
drain the refrigerant oil from the component being
replaced into a graduated container. On assembly,
add the quantity of refrigerant oil drained to the new
component.
Compressor
A new compressor is sealed and pressurised with
Nitrogen gas. When fitting a new compressor, slowly
release the sealing cap; gas pressure should be
heard to vent as the seal is broken.
CAUTION: A new compressor should always be
sealed and could be pressurised with nitrogen
gas. To avoid possible oil loss, release the
sealing cap(s) slowly. Do not remove the cap(s)
until immediately prior to connecting the air
conditioning pipes to the compressor.
Rapid refrigerant discharge
If the air conditioning system is involved in accident
damage and the system is punctured, the refrigerant
will discharge rapidly. The rapid discharge of
refrigerant will also result in the loss of most of the oil
from the system. The compressor must be removed
and all the remaining oil in the compressor drained
and refilled as instructed in the air conditioning
section of this manual.