25 15. A/C SYSTEM SERVICING (Contd)
d. Flushing System
Discharge A/C system (refer to task c.).
Fill flushing cylinder (2) with flushing agent.
l Never flush compressor. Flushing removes oil. Damage to
compressor will result if compressor is flushed.
l Air conditioning system flushing is essential when replacing
failed compressors. Failure to flush A/C systemwill result in
damage to new compressor.
l Do not attempt to use R-134a as a flushing agent. R-134a will
not remain a liquid at ambient temperatures. Use R-111 or
R-113 for flushing purposes.
l Flushing is done to remove solid materials such as oil, sludge,
and metal particles from failed components.
l For a complete system flush, tools must be installed at A/C lines
Eye protection must be worn when using compressed nitrogen.
Failure to do so may result in injury to personnel.
Pressurize flushing cylinder (2) with compressed nitrogen to 100 psi (690 kPa>.
Connect flushing gun (3) to flushing cylinder (2).
l Perform steps 5 through 7 an condenser, evaporator, and
refrigerant lines. Continue flushing until there is no evidence of
oil or contaminants.
l Illustration shows flushing of condenser. Procedure is similar
for flushing of other components.
Insert flushing gun (3) into refrigerant outlet tube (4) of component to be flushed.
Connect a rubber hose (7) over inlet (5) of component to be flushed, and place other end of hose (7) in
a drain pan (6).
Open flushing gun (3) to blow cleaning agent through component.
Remove rubber hose (7) from component and plug refrigerant line.
Remove flushing gun (3) from component and plug refrigerant line.