Chevrolet BEAUVILLE SPORTVAN G10 SERIES, Service Manual

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A IR C O N D IT IO N IN G 1A-15
• A five am pere tim e delay cartidge fuse has been installed
in th e com m on line to p ro te c t the w indings o f the
com pressor. The fuse will blow if an excessive load is
placed on th e pum p. In the event th e fuse is blow n,
replace w ith a five am pere tim e delay fuse — do n o t use
a su b stitu te fuse as it will result in dam age to the starting
windings.
• I f the pum p is being utilized to evacuate a b u rn t-o u t
system , a filter m ust be co n n e cted to th e intake fitting to
prevent any sludge from contam in atin g the w orking
p arts, w hich will result in m alfu n ctio n o f th e pum p.
• Do n o t use th e vacuum pum p as an air com pressor.
LEAK TESTING THE SYSTEM
W henever a refrigerant leak is suspected in the system o r a
service o p era tio n p erform ed w hich results in disturbing lines or
connections, it is advisable to test for leaks. C om m on sense
should be th e governing fac to r in perform ing any leak te st,
since the necessity and e x te n t o f any such te st will, in general,
depend u p o n th e n a tu re o f th e com plaint and th e ty p e o f
service perfo rm ed on th e system .
C A U T IO N : The use o f a leak detecting dye w ith in
the system is not recommended because o f the
follow ing reasons:
1. R efrigerant leakage can exist w ith o u t any oil leakage. In
this case the dye will n o t indicate the leak, how ever, a
to rch d ete c to r will.
2. The ad d itio n o f additives, o th e r th a n in h ib ito rs, m ay
alter th e stability o f the refrigeration system and cause
m alfunctions.
3. Dye ty p e leak d etecto rs, w hich are insoluble, form a
curdle w hich can b lock th e inlet screen o f the expansion
valve.
Leak Detector
T ool J-6084 (fig. 23) is a propane gas-burning to rch w hich
is used to locate a leak in any p a rt o f th e system . R efrigerant
gas draw n in to the sampling tu b e attac h ed to th e to rc h will
cause the to rc h flame to change color in p ro p o rtio n to the size
o f the leak. P ropane gas fuel cylinders used w ith th e to rch are
readily available com m ercially th ro u g h o u t the co u n try .
W A R N IN G : Do not use lighted detector in any
place where combustible or explosive gases, dusts or
vapors may be present.
Operating Detector
1. D eterm ine if there is sufficient refrigerant in th e system
for leak testing.
2. O pen co n tro l valve only until a low hiss o f gas is heard,
then light gas at opening in chim m ey.
3. A djust flam e un til desired volum e is o btained. This is
m ost satisfactory w hen blue flam e is approxim ately 3 /8 ”
above reactor plate. T he reacto r p late will quickly h eat to
a cherry red.
4. E xplore for leaks by m oving th e end o f th e sampling hose
aro u n d possible leak p oints in the system . Do n o t pinch
or k in k hose.
Fig. 2 3 —Leak Detector
N O T E : Since R -1 2 is heavier than air, it is good
practice to place open end of sampling tube
im m ediately below point being tested, particularly
in cases o f small leaks.
W A R N IN G : Do not breathe the fumes th at are
produced by the burning R -12 gas in the detector
flam e, since such fumes can be to x ic in large
concentrations of R-12.
5. W atch for color changes. The color o f th e flam e w hich
passes th ro u g h th e reactio n plate will change to green or
yellow-green w hen sam pling hose draws in very small
leaks o f R -12. Large leaks will be in d icated by a change
in color to a brilliant blue or p urple. W hen th e sampling
hose passes th e leak, th e flam e will clear to an alm ost
colorless pale blue again. O bservations are best m ade in a
sem i-darkened area. I f th e flam e rem ains yellow w hen
u n it is rem oved fro m leak, insufficient air is being drawn
in or the reactor p late is dirty.
N O T E : A refrigerant leak in the high pressure side
of the system may be more easily detected if the
system is operated fo r a fe w minutes, then shut o ff
and checked im m ediately (before system pressures
equalize). A leak on the low pressure side may be
more easily detected after the engine has been shut
o ff fo r several minutes (system pressures equalized);
this applies particularly to the fro n t seal.
A V A IL A B IL IT Y OF R E FR IG ER A N T-12
R efrigerant 12 is available in 30 lb. and in 15 oz. disposable
containers.
CHIMNEY
REACTION PLATE
BURNER HEAD
BURNER TUBE
ASSEMBLY
SAMPLING TUBE
PROPANE GAS
CYLINDER
C H E V Y V A N S H O P M A N U A L