best methods to flush any Auto A/C system:
that flushing the A/C system is really all about cleaning the inside of a
very long, long tube. In order to do the best job, you should always break
the system apart into the smallest possible pieces. That means disconnecting
all the hoses and components and flushing them individually.
basic concept behind any flush job is really to remove the oil and contaminants
from the A/C system. In most cases, contaminants and debris will 'stick'
to the oil. If you can remove all the oil, you will remove all the contamination.
use an approved flush solvent. Approved A/C system flush solvents will
always evaporate quickly and not leave any residue. That's important because
O.E. Parts suppliers advise that the biggest so called 'warranty' claim on
A/C compressors can be traced back to problems where residual flush solvents
left in the system caused a break down of lubrication. Also be sure
to flush all components in both directions until the flush leaving the
component is clean.
use oil based flush solvents. These were developed as an 'answer'
to vehicle manufacturer's suggestions that A/C systems should not be
flushed. The oil based flush solvents do not eliminate the debris and never
evaporate completely from the A/C system.
or Liquid Pour flushes?
the right flush solvent is important. Typically, most 'liquid pour' flush
solvents require the use of a flush gun in order to 'push' the flush
into the A/C system. In cases where flush guns are not available, an acceptable
solution is to use the 'Aerosol' flush. The aerosol flush can acts like
a flush gun to 'push' the flush solvent into the A/C system. In both cases,
you will still require dry compressed shop air or nitrogen to assure
all the flush is pushed through the component and out of the
not to flush:
any auto A/C system, you should never attempt to flush the A/C compressor,
the receiver drier or accumulator, expansion valve or any muffler assembly
that may be located between the compressor and condenser.
and accumulators will have to be replaced. Likewise, you will never be able
to remove all the debris from any muffler assembly, so they too will have
to be replaced or eliminated from the system. Where you suspect a plugged
expansion valve, inlet screens can be cleaned. If your valve is not equipped
with an inlet screen and it is restricted, it will have to be replaced.