Air Conditioning Procedures; Torque Levels For The Hose Connections; Depressurising; Recovering Refrigerant - Aston Martin DB7 Workshop Manual

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Air Conditioning
Torque Settings / Depressurising the System
Torque Levels for the Hose Connections
COMPONENT TORQUE Nm
Evaporator Hose
Hose to Expansion Valve 32.0 ± 4.0
Hose to Compressor 34.0 ± 2.0
Condenser Hose
Hose to Compressor 34.0 ± 2.0
Hose to Compressor 25.0 ± 4.0
Condenser Pipe
Pipe to Drier Bottle 6.0 ± 1.5
Evaporator Pipe
Pipe to Expansion Valve 16.0 ± 1.5
Air Conditioning Procedures
Depressurising
Note: Observe all safety precautions and do not smoke
while carrying out the following procedures.
1. With the engine switched off, remove the protective
caps from the schraeder valves.
2. Ensure the manifold gauge set hand valves are in
the closed position, then by using the access valve
core remover connect the manifold gauge set to the
system with the red hose to the high pressure side
and the blue hose to the low pressure side.
3. Screw out the valve core to allow the refrigerant to
flow.
4. Place the centre hose of the manifold set into a
suitable container.
5. Slowly open the high or low side manifold hand
valve and adjust the valve for a smooth refrigerant
flow. Watch the refrigerant for any signsof escaping
oil and adjust the hand valve to prevent any oil
escaping.
6. If oil islostduringthedischarge,thecompressoroil
level must be checked and if necessary topped up.
7. As the discharge rate slows down, open the other
manifold hand valve so that refrigerant flows from
both high and low pressure sides of the system.
8. Constantly adjust the hand valves to ensure that oil
does not flow. When a zero reading is shown on
both high and low pressure gauges the system is
discharged.
8. Close both manifold hand valves.
Recovering Refrigerant
Caution: The Recovery-Recycle-Recharging equipment
has special fittings to avoid cross contamination with R-
12 systems. Do not attempt to adapt this unit for R-12 as
system failure will result.
Warning: Follow the safety procedures as defined at the
beginning of the section.
Caution: The unit's overfill limitation mechanism has
been calibrated specifically for use with the 50 lb. (23 Kg)
refillable refrigerant tank.
As the refrigerant is recovered it is passed through
an oil separator and a filter drier before it is allowed
to enter the refrigerant tank. When it is dry the
moisture indicator turns green.
May 1996 8-47