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ii. RECOVERY AND RECYCLING
The following procedure is usual for the use of Re-
frigerant Recovery, Recycling and Recharging
station or Refrigerant Recovery Unit (RRU) when
recovering refrigerant from a car air conditioning sys-
tem.
1. Connect a Refrigerant Station to the high and
low pressure servicing connections located in-
side hood.
2. Operate the refrigerant recovery system accord-
ing to the manufacturer’s instructions and
recover the refrigerant and oil from the vehicle.
3. Measure the amount of oil discharged from the
system. Add an equal amount of new refrigerant
oil before evacuation operation.
CAUTION
•
Refrigerant must always be recycled before re-
use, to ensure that the purity of the refrigerant is
high enough for safe use in the air conditioning
system
•
R134a Refrigerant Recovery Recycling Recharg-
ing Station must not be used with any other type
of refrigerant.
iii. EVACUATION AND RECHARGING
1. Add refrigerant oil as per the table given in “Re-
plenishing Compressor Oil” procedure in the
same section.
2. Evacuate the system according to the manufac-
turer’s instructions.
NOTE
If the vacuum reading is below 700mmHg after 15
minutes, suspect a leak in the system. Partially re-
charge the system and check for leaks by using leak
detector. Check suction lines first, then run the com-
pressor for 5 minutes and then check the high-
pressure lines.
CAUTION
The system must be evacuated immediately before
recharging commences. Delay between Evacuation
and Recharging is not permitted.
3. Recharge the refrigerant as per instructions. Re-
frigerant to be charged in the system is 580±20
gms.
NOTE
When charging refrigerant only without replacing any
component, replenish the same amount of measured
oil when recovering refrigerant (if not measured, re-
plenish 30cc oil).
4. If the full charge has not been accepted by the
system, start the compressor and run it for a
minimum of 2 minutes. Switch ON the air condi-
tioning system, open the vehicle windows, set
the temperature control to full cold and run the
blower at maximum speed.
5. Consult Refrigerant Station Manual for correct
procedure to complete the charge.
6. Carry out the air conditioning system perfor-
mance test.
iv. FLUSHING OF AC SYSTEM
Whenever there is an AC compressor failure the AC
system should be flushed. This is done in order to
remove the debris of the AC compressor that might
have circulated through the system.
The compressor used is piston type compressor.
Flushing can be either done using an inverted de-
canting R134a cylinder filled with refrigerant. In some
recovering devices a flushing port is provided.
NOTE
•
If a compressor is replaced without flushing, de-
bris would circulate throughout the system.
Hence all the components should be flushed.
•
Flushing also removes excess oil from the sys-
tem. If you suspect the system contains too
much oil, flushing is a way to start fresh so you
can establish the correct quantity of refrigerant
oil in the system.
Following points should be noted while perform-
ing a flushing process
1. Flush individual components.