300Tdi Discovery
82
AIR CONDITIONING
6
ADJUSTMENT
SYSTEM TEST
1. Place the vehicle in a ventilated, shaded area
free from excessive draught, with the doors and
windows open.
2. Check that the surface of the condenser is not
restricted with dirt, leaves, flies, etc. Do not
neglect to check the surface between the
condenser and the radiator. Clean as necessary.
3. Switch on the ignition and the air conditioner air
flow control. Check that the blower is operating
efficiently at low, medium and high speeds.
Switch off the blower and the ignition.
4. Check that the evaporator condensate drain
tubes are open and clear.
5. Check the tension of the compressor driving belt,
and adjust if necessary.
6. Inspect all connections for the presence of
refrigerant oil. If oil is evident, check for leaks,
and repair as necessary.
NOTE: The compressor oil is soluble in
Refrigerant R134a and is deposited when
the refrigerant evaporates from a leak.
7. Start the engine.
8. Set the temperature controls to cold and switch
the air conditioner blower control on and off
several times, checking that the magnetic clutch
on the compressor engages and releases each
time.
9. With the temperature control at maximum
cooling and the blower control at high speed,
warm up the engine and fast idle at 1000
rev/min. Check the sight glass for bubbles or
foam. The sight glass should be generally clear
after five minutes running, occasional bubbles
being acceptable. Continuous bubbles may
appear in a serviceable system on a cool day, or
if there is insufficient air flow over the condenser
at a high ambient temperature.
10. Repeat at 1800 rev/min.
11. Gradually increase the engine speed to the high
range, and check the sight glass at intervals.
12. Check for frosting on the service valves.
13. Check the high pressure hoses and connections
by hand for varying temperature. Low
temperature indicates a restriction or blockage at
that point.
14. Switch off the air conditioning blower and stop
the engine.
15. If the air conditioning equipment is still not
satisfactory, carry out a pressure test as
previously described in this section.
COMPRESSOR DRIVE BELT
Service repair no - 82.10.01.
Tdi -
See ENGINE, Repair, Compressor drive belt
V8i and Mpi
See ENGINE, Repair, Drive belt
