Land Rover Defender: Air Conditioning (A/C) System Precautions
The A/C system contains fluids and components which could be potentially
hazardous to the service engineer or the
environment if not serviced and handled correctly. The following guidelines are
intended to alert the service engineer
to potential sources of danger and emphasise the importance of ensuring the
integrity of the A/C operating conditions
and components installed to the vehicle.
Where necessary, additional specific precautions are detailed in the relevant
sections of this Manual and also in the
Health and Safety Section. These precautions must be referred to prior to
commencing repair operations.
The refrigerant used in the A/C system is HC-134a (Hydrofluorocarbon) R134a.
WARNINGS:
- Servicing must only be carried out by personnel familiar with both
the vehicle system and the charging and
testing equipment. All operations must be carried out in a well ventilated
area away from open flame and
heat sources.
- R134a is a hazardous liquid and when handled incorrectly can cause
serious injury. Suitable protective
clothing, consisting of face protection, heat proof gloves, rubber boots and
rubber apron or waterproof
overalls, must be worn when carrying out operations on the A/C system.
Remedial actions
WARNING:
Due to its low evaporating temperature, R134a must be handled with care. R134a
splashed on any part of
the body will cause immediate freezing of that area. Also, refrigerant cylinders
and replenishment trolleys
when discharging will freeze skin to them if contact is made.
If an accident involving R134a should occur, conduct the following remedial
actions:
- If liquid R134a enters the eye, do not rub it. Gently run large
quantities of eye wash over affected eye to raise the
temperature. If an eye wash is not available, cool, clean water may be used
to flush the eye. After rinsing, cover
the eye with a clean pad and seek immediate medical attention.
- If liquid R134a is splashed onto the skin, run large quantities of water
over the affected area to raise the
temperature. Implement the same action if the skin comes in contact with
discharging cylinders. Wrap the
contaminated body parts in blankets (or similar materials) and seek
immediate medical attention.
- If the debilitating effects of inhalation of R134a vapour are suspected,
seek fresh air. If the affected person is
unconscious, move them away from the contaminated area to fresh air and
apply artificial respiration and/or
oxygen and seek immediate medical attention.
Service precautions
Observe the following precautions when handling components used in the
system:
- A/C units must not be lifted by their hoses, pipes or capillary lines.
- Hoses and lines must not be subjected to any twist or stress; the
efficiency of the system will be impaired by kinks
or restrictions. Make sure that hoses are correctly positioned before
tightening couplings, and make sure that all
clips and supports are utilised.
- Flexible hoses should not be positioned closer than 100 mm (4.0 in) to
the exhaust manifold unless protected by
heat shielding.
- 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.
- 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.
- Before connecting any hose or pipe, make sure that refrigerant oil is
applied to the seat of the new O-rings, BUT
NOT to the threads of the connection.
- All protective plugs or caps must remain in place in the component until
immediately prior to connection.
- Make sure components are at room temperature before
uncapping/unplugging, to prevent condensation of
moisture from the air that enters it.
- When disconnecting, immediately plug or cap all pipes to prevent ingress
of dirt and moisture into the system.
- Components must not remain uncapped/unplugged, if a system has been left
uncapped/unplugged for 24 hours or
longer, a new receiver/drier must be installed.
- The receiver/drier contains desiccant which absorbs moisture. It must be
positively sealed at all times. A receiver
/drier that has been left uncapped for longer than 24 hours must not be
used; install a new unit.
- The receiver/drier should be the last component connected to the system
to make sure optimum dehydration and
maximum moisture protection of the system.
- Use alcohol and a clean lint-free cloth to clean dirty connections.
- Make sure that all new parts installed are marked for use with R134a.
- When a major repair has been completed, a leak test should be conducted;
refer to the Repairs Section of this
manual for the correct procedure.
Refrigerant oil
CAUTION:
Refrigerant oil (ND-8 PAG) 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.
When replacing components in the 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 - See Compressor
Replacement in this Section.
A/C Compressor
A new compressor is sealed and pressurised with Nitrogen gas. When installing
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 should 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
pipes to the compressor.
Rapid refrigerant discharge
If the A/C system is damaged as a result of an accident 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.
Precautions for refrigerant recovery, recycling and recharging
When the A/C system is recharged, any existing refrigerant is first recovered
from the system and recycled. The
system is then charged with the required weight of refrigerant and volume of
refrigerant oil.
WARNING:
Refrigerant must always be recycled before re-use to make sure that the purity
of the refrigerant is high
enough for safe use in the system. Recycling should always be carried out with
equipment which is design
certified by Underwriter Laboratory Inc. for compliance with SAE J1991. Other
equipment may not recycle
refrigerant to the required level of purity.
CAUTIONS:
- A R134a Refrigerant Recovery Recycling Recharging Station must not be
used with any other type of
refrigerant. Refrigerant R134a from domestic and commercial sources must not
be used in motor vehicle
systems.
- The system must be evacuated immediately before recharging commences.
Delay between evacuation
and recharging is not permitted.
A/C Compressor Replacement
A new compressor is supplied filled with a full charge (X cm³) of refrigerant
oil.
A calculated quantity of oil must be drained from the new compressor before
installation. To calculate the quantity of
oil to be drained:
- Remove the drain plug from the old compressor.
- Invert the compressor and gravity drain the oil into a calibrated
measuring cylinder. Rotate the compressor clutch
to make sure the compressor is completely drained.
- Note the quantity of oil drained (Y cm³).
- Calculate the quantity of oil to be drained from the new compressor
using the following formula: X cm³ - (Y cm³ +
20 cm³) = Q cm³
- Remove the drain plug from the new compressor and drain Q cm³ of oil.
Install and tighten the compressor drain
plug.
Vehicle Weights
* Weight quoted is the maximum weight possible for vehicles in this model
range; weights may be less for
certain variants depending upon trim level, territorial requirements etc.
Vehicle Dimensions
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DESCRIPTION AND OPERATION
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Always handle all solvents, sealers and adhesives with extreme care. Some
contain chemicals or give off
fumes which can be dangerous to health. Always foll
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WARNINGS:
Only qualified technicians are allowed to work on pyrotechnic
components.
INHALED: Exposure to pyrotechnic residue may cause low blood
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DESCRIPTION AND OPERATION
NOTE:
For additional information on systems/components that must be checked, refer to
the relevant section in the
Workshop Manual.
Vehicle inspections may be carried out for
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REMOVAL AND INSTALLATION
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REMOVAL
WARNINGS:
To avoid accidental deployment and possible personal injury, the
backup power supply must be depleted
before repairing or replacing any airbag Supplementary Restraint System
(SRS) components. To deplete
the backup power supply energy, disco
Make sure to read and fully understand
the following warnings before using any
of the features in this section.
Failure to observe warnings and
cautions may result in vehicle damage,
injury, or DEATH in the event of an
accident.
High speed impacts may cause serious
injury or death, irrespective of
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