liquid refrigerant to flush the system, and finishing up with an
in-liquid-line filter, is a General Motors- recommended alternative to
the terpene and petrochemical solvents. It does a good job of removing
oil and minor debris (such as desiccant particles), but is time
consuming. Further, recovering liquid refrigerant that fills the
system is not some quick operation, and it requires a recovery machine
designed for refrigerant flushing, including a special port. GM
requires its dealers to get permission to perform it under warranty.
Substantially too much oil
in the system, however, is not something you can ignore. If you want
to refrigerant- flush, be aware of the full GM procedure, which is
described later in this report (see REPEAT DENSO FAILURES ON CHEVY
TAHOE/GMC YUKON AND SUBURBAN
WITH REAR AIR) and
GM bulletin No. 01-01- 38-006-D, issued 9/14/04).