Chevrolet BEAUVILLE SPORTVAN G10 SERIES, Руководство по обслуживанию

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A IR C O N D IT IO N IN G 1A-22
Check for Defective Valve
The following procedure m ust be follow ed to determ ine if a
m alfunction is due to a defective expansion valve.
1. Check to determ ine if th e system will m eet the p er­
form ance te st as o u tlin ed previously. If th e expansion
valve is defective, th e low pressure readings (evaporator
pressure) will be above specification.
2. The loss o f system perform ance is n o t as evident w hen
th e com pressor head pressure is below 200 PSI. T h ere­
fore, it m ay be necessary to increase the system head
pressure b y partially blocking the condenser. D isconnect
the blow er lead wire an d repeat the “ P erform ance
C heck” to determ ine if the evaporator pressure can be
o btained.
3. The system will also in dicate a low refrigerant charge by
bubbles occurring in th e sight glass.
Fig. 2 8 —Expansion Valve
COMPONENT PART REPLACEMENT
PREPARING SYSTEM FOR
REPLACEMENT OF COMPONENT PARTS
Air conditioning, like m any o th e r things, is fairly simple to
service once it is u n d ersto o d . H owever, there are certain
procedures, practices an d precau tio n s th a t should be follow ed.
F o r this reason it is strongly recom m ended th a t th e preceding
in fo rm atio n in this section be studied thoro u g h ly before
atte m p tin g to service th e system .
G reat em phasis m ust be placed upon keeping th e system
clean. Use plugs o r caps to close system co m p o n en ts and hoses
w hen th e y are opened to th e atm osphere. Keep yo u r w ork
area clean.
In rem oving and replacing any p art w hich requires unsealing
th e refrigerant circuit th e follow ing o perations, w hich are
described in this section, m ust be p erform ed in th e sequence
show n.
1. Purge the system by releasing the refrigerant to the
atm osphere.
2. R em ove an d replace th e defective p art.
3. E vacuate, charge an d check th e system .
W A R N IN G : Always wear protective goggles when
w orking on refrigeration systems. Goggles J-5453
are included in the set o f air conditioning special
tools. Also, beware o f the danger o f carbon m on­
oxide fumes by avoiding running th e engine in
closed or im properly ventilated garages.
FO REIG N M A T E R IA L IN THE SYSTEM
W henever foreign m aterial is fo u n d in th e system , it m ust
be rem oved before restoring the system to o peration.
In the case o f com pressor m echanical failure, perform the
follow ing o p e ra tio n s:
1. Rem ove th e com pressor.
2. Rem ove the receiver-dehydrator and discard the unit.
3. Flush the condenser to rem ove foreign m aterial w hich
has been p u m p e d in to it.
4. D isconnect the line from th e receiver-dehydrator a t th e
inlet screen for th e presence o f m etal chips or o ther
foreign m aterial. I f th e screen is plugged, replace it.
R econnect the line to th e expansion valve.
5. Install a new receiver-dehydrator.
6. Install the replacem ent com pressor.
7. A dd the necessary q u a n tity o f oil to the system (one
fluid ounce because o f receiver-dehydrator replacem ent
plus th e q u an tity needed for the replacem ent co m ­
pressor — see “ C hecking C om pressor Oil Charge” under
“ C hecking O il.”
8. Evacuate, charge and check the system .
R E FR IG E R A N T LIN E CONNECTIONS
"O " Rings
Always replace th e “ 0 ” ring w hen a conn ectio n has been
broken. When replacing the “ O ” ring, first dip it in clean
refrigeration oil. Always use a backing w rench on “ O ” ring
fittings to prevent the pipe from tw isting and dam aging the
“ 0 ” ring. Do n o t overtighten. C orrect torq u e specifications are
as follows:
CAPILLARY BULB
OUTLET
C H E V Y V A N SHO P M A N U A L