Handling Insufficient Refrigerant Level; Handling Compressor Oil; Refrigeration Cycle - Aston Martin V8 Vantage Workshop Manual

Air Conditioning (A/C) System (12.03)
Climate Control (12.00)

Handling Insufficient Refrigerant Level

If an insufficient refrigerant level is detected while
troubleshooting, do not charge (add) the refrigerant.
Because an accurate amount of refrigerant cannot be
determined from the pressure indicated on the
recovery / recycling / recharging unit, never charge the
If there is too much or too little refrigerant from the
refilling, there may be secondary problems such as
damage to the refrigerant cycle parts, or a decrease of
cooling performance. Therefore, if it is determined that
the refrigerant level is insufficient, completely remove
refrigerant from the refrigerant cycle and refill with
refrigerant to the specified amount.

Handling Compressor Oil

Use only ND8 compressor oil for this vehicle. Using a
PAG oil other than DENSO OIL8 compressor oil will
damage the A/C compressor.
Do not spill the ND8 compressor oil on the vehicle. A
drop of compressor oil on the vehicle surface can
damage the paint work. If oil gets on the vehicle, wipe
it off immediately.
ND8 compressor oil has a high moisture absorption
efficiency. If moisture mixes with the compressor oil,
the refrigerant system could be damaged. Ensure caps
are installed immediately after using the compressor oil
or removing refrigerant system parts to prevent
moisture absorption.
12-3-4
Caution
refrigerant.
Caution
Caution
Caution
Caution

Refrigeration Cycle

Operation
1. The Compressor (1) draws low pressure, low
temperature, refrigerant vapour from the evaporator (5)
and compresses it, raising the refrigerant pressure and
temperature.
2. This high pressure, hot, refrigerant vapour enters the
condenser (2), where it is cooled by the flow of ambient
air and changes state into a cooler, high pressure liquid.
3. From the condenser, the liquid passes into the receiver
drier (3) which has three functions:
• Removes moisture from the refrigerant using a
desiccant
• Filters the refrigerant to remove system contaminants
• Stores the refrigerant to cope with varying system
refrigerant demands
4. The filtered liquid refrigerant, still at high pressure, then
enters the expansion valve (4). Here it passes through a
controlled orifice and emerges as an atomised liquid
spray. This has the effect of reducing the refrigerant
pressure and temperature. The cold refrigerant spray
now flows into the evaporator (5).
5. As refrigerant passes through the evaporator core, it
cools the incoming airflow. Heat is absorbed by the
refrigerant, during this process and it once again changes
state, from an atomised cool liquid into a vapour. The
refrigerant vapour then returns to the compressor for the
cycle to be repeated.
An automatic safety valve is incorporated in the compressor,
which will open if the system pressure rises above 41 bar.
The valve will reseat when the pressure drops below 27,6
bar. When the safety valve is open, the compressor will 'free
Workshop Manual October 2005