Perform task f.).
f. Checking/Adding Refrigerant Oil.
· It is not necessary to check or add
oil as routine maintenance. It is
necessary to check oil when the
compressor, or receiver/dryer has
been replaced, or there was an
obvious oil leak. When a system
is discharged, it is also necessary
to replace any oil carried out with
· Vehicle must be on level ground.
Charge A/C system (refer to task e.).
Make sure low pressure gage valve (1)
and high pressure gage valve (2) on
manifold gage set (3) are turned
clockwise to off position.
Start engine and turn on A/C system
(refer to TM 10-3930-673-10). Allow
engine to idle for approximately 10 to
15 minutes. Stop engine.
· Do not allow refrigerant R-134 to
escape too quickly. Refrigerant oil
· When high pressure gage and low
pressure gage read "zero", the
compressor is discharged.
Turn low pressure gage valve (1) and
high pressure gage valve (2)
counterclockwise slightly to permit refrigerant in the compressor (5) to slowly escape
through center hose (4) until gages read "zero".
Close low pressure gage valve (1) and high pressure gage valve (2).
Remove fill plug dipstick (6) from compressor (5) and wipe clean.
Insert the dipstick to its stop position.
Remove dipstick from compressor (5) and count number of increments oil level is up to