Winnebago 1987-1989 LeSharo Service Manual page 602

SERVICING THE AlC SYSTEM
RECEIVING-DRIER REPLACEMENT INTERVALS
The receiver-drier cannot be serviced and should be
replaced whenever there is reason to believe the
dessiccant has become saturated with moisture or
if there is any doubt as to its correct functioning.
A quick check of the receiver-drier can be made by
feeling the receiver-drier and the inlet and outlet
hoses or refrigerant lines with the system
operating. These should be warm to the touch. A
cool receiver-drier or lines indicates a malfunction.
Receiver-Drier must be replaced at certain
intervals.
In regular operation, the following replacement
schedule should be used:
Normal Conditions - Replace receiver-drier every
third time the system is opened for repair or
servicing.
Special Conditions - Replace receiver-drier each
time the system is opened when operated under
the following conditions.
1. In a high humidity area (high moisture content
in the air.)
2. If the system has been open for a long period
as when an existing leak (broken hoses, loose
connections, etc) has allowed air and moisture
to enter the system.
3. Whenever thermostatic expansion valve is
replaced (usually because of corrosion caused
by moisture in system).
4. Whenever the receiver-drier or the outlet
hoses or lines are cool to the touch with
system operating.
S. When cloudiness is noted in the sight glass.
MOISTURE CONTAMINATION
Moisture in system will cause a corrosive acid to
form.
Any moisture in the air conditioning system is
extremely harmful. Moisture not absorbed by the
desiccant in the receiver-drier will circulate with
the refrigerant and droplets may collect and freeze
in the Thermostatic Expansion Valve orifice. This
would block the refrigerant flow and stop the
cooling action. Also, moisture will react with
Refrigerant-12 to form a hydrochloric acid which
will cause corrosion of the metal parts in the
system. Corrosion particles may become detached
and block the small passages and orifices in the
system.
Moisture must not be allowed to enter the air
conditioning system and the receiver-drier must be
replaced when the desiccant becomes saturated
and can no longer remove moisture from within
the system.
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