open gas tank ASTON MARTIN DB7 1997 Workshop Manual

Air Conditioning
Refrigerant Recovery and Recycling ^=2?
Recovery Procedure
Hote:
Run the
air-conditioning
system
for
a
few
minutes
before starting the
recovery
procedure as
this will
enable

more refrigerant to be recovered. Turn the
system
off
before
starting
the procedure.

1.
Attach the red (high side) hose oftheunittothe high
side fitting of the system on the vehicle then fit the
blue (low side) fitting to the low side on the vehicle.
Note: Make sure that the Air conditioning
system
has
pressure in it before beginning the recovery
process;
if
there is no
system
pressure there is no refrigerant to

recover.
Also
make sure that the
oil
drain
valve
is
closed.

2. Open both the high and low side valves on the
control panel.
3. Open the red CAS (vapour) valve and the blue
LIQUID valve on the tank.

4.
Turn on the MAIN POWER switch.
5. Press the RECOVERY key on the key-pad. The
display shows that the unit in the RECOVER mode
and AUTOMATIC cycle. After the compressor starts
the display shows the weight of refrigerant being

recovered.
The compressor shuts off automatically
when the recovery is complete and the display
shows the message 'CPL' and the final weight of the
recovered refrigerant.
6. Wait for five minutes and watch the manifold
gauges for a rise above 0. If a rise occurs press the
HOLD/CONT key. Repeat as needed until the
system pressure holds for two minutes.
Note: Drain the oil
separator
after
each
job.
7. Slowly open the oil drain valve and drain the oil
into the oil catch bottle. When all the recovered oil
has completely drained close the valve.
8. Replace oil lost during the recovery procedure by
measuringthe amount of oil inthe catch bottle and
adding the same amount of new oil to the system.
Note:
Dispose
of the
recovered
oil in an approved way.
9. When the recovery tank is full the compressor is
shut off and the display shows the message FULL.
Evacuating and Recycling the Refrigerant

1.
Open the red (high side) and the blue (low side)
valves on the unit and open the red GAS (vapour)
valve and the blue LIQUID valve on the tank.

2.
Enter the required time using the key-pad, press
enter,thedisplayshowstheenteredtime in minutes.
3. Start the vacuum pump by pressing the VACUUM
KEY again. The recycling process begins
approximately five seconds after the vacuum pump
starts and the message RECYCLE is displayed.
Note: If the vacuum pump
has
run for ten hours or
over

without an oil change the
message
OIL
flashes
on the
display.
Change
the pump oil and
then press
the
SHIFT/

RESET key and
the
zero key to
reset the
oil
change
timer
to zero.
The digital display counts down the evacuation

time.

4.
Check for non-condensibles after five minutes

recycling.
Ifthegauge needles are more than lOpsi
apart purge the non-condensibles from the tank by
open
i ng
the purge valve on the back of the
un
it and
continue to bleed until both needles show the same

reading.

The vacuum sequence continues until the
programmed time has elapsed at which point the
message CPL is displayed.
5. If the moisture indicator turns green recharge with
refrigerant.
or
5. If the moisture indicator has not turned green
replace the unit's filter-drier, which is probably

saturated.

Note:
Pressing
any key at this point allows the next
function to be
accessed.

To recycle the refrigerant only without pulling a
vacuum for an indefinite period of time press the
SHIFT/RESET key and the RECYCLE key on the key­

pad.
Press the SHIFT/RESET key to cancel.
For vacuum only press the SHIFT/RESET key and
the ENTER key and then press
"1".
Run the vacuum
pump as long as required and then press
"1"
or
press SHIFT/RESET to cancel.
8-48 May 1996