M Ain Tain In G C Hem Ical S Tability In Th E R E Frig E Ra Tio N S Ystem; J-8393 Charging Station - Chevrolet CHEVY VAN G10 SERIES Service Manual

o f gauge readings. O pen very slowly, keeping face and
hands away so th a t no injury can occur if there happens
to be liquid refrigerant in the line. I f pressure is noticed
w hen fitting is loosened, allow it to bleed o ff as
described under "Purging the S ystem " in this section.
W A R N I N G : Always
when opening refrigerant lines.
• In th e event any line is opened to atm osphere, it should
be im m ediately capped to prevent entrance o f m oisture
and dirt.
• The use o f th e proper w renches w hen making con­
nections on " O" ring fittings is im p o rtan t. The use o f
im proper wrenches m ay damage the connection. The
opposing fitting should always be backed up w ith a
w rench to prevent distortion o f connecting lines or
com ponents. When connecting th e flexible hose con­
nections it is im portant th a t the swaged fitting and flare
n u t, as well as th e coupling to w hich it is attached, be
held at the same tim e using three different wrenches to
prevent turning the fitting and damaging the ground seat.
• " 0 " rings and seats m ust be in perfect co ndition. The
slightest b urr or piece o f dirt m ay cause a leak.
• Sealing beads on hose clam p connections m ust be free o f
nicks and scratches to assure a p erfect seal.
M A IN T A IN IN G CHEM ICAL S T A B ILITY IN THE
RE FR IG E R A TIO N SYSTEM
The m etal internal parts o f the refrigeration system and the
refrigerant and oil contained in the system are designed to
rem ain in a state o f chem ical stability as long as pure R-12 and
uncontam inated refrigeration oil is used in the system.
However, w hen abnorm al am ounts o f foreign m aterials,
such as d irt, air or m oisture are allow ed to enter the system ,
the chem ical stability m ay be upset. When accelerated by h eat,
these contam inants may form acids and sludge and eventually
cause the breakdow n o f com ponents w ithin the system . In
ad dition, contam inants m ay effect the tem perature- pressure
relationship of R-12, resulting in im proper operating tem pera­
ture and pressures and decreased efficiency o f th e system.
C A U T IO N : The follow ing general practices should
be observed to insure chemical stability in the
system.
• Whenever it becom es necessary to disconnect a refriger­
ant or gauge line, it should be im m ediately capped.
Capping the tubing will also prevent d irt and foreign
m atter from entering.
• Tools should be k ep t clean and dry. This also includes
the gauge set and replacem ent parts.
• When adding oil, th e container should be exceptionally
clean and dry due to the fact that th e refrigeration oil in
the container is as m oisture-free as it is possible to make
it. T herefore, it will quickly absorb any m oisture w ith
w hich it com es in co n tact. F or this same reason the oil
container should be capped im m ediately after use.
• When it is necessary to open a system , have everything
y o u will need ready and h andy so th a t as little tim e as
possible will be required to perform the operation. D on't
wear safety goggles
leave the system open any longer th an is necessary.
• Finally, after the operation has been com pleted and the
system sealed again, air
evacuated fro m the system before recharging.

J-8393 CHARGING STATION

The J-8393 Charging S tatio n is a portable assembly o f a
vacuum pum p, refrigerant supply, gauges, valves, an d m ost
im p o rta n t, a five (5) po u n d m etering refrigerant charging
cylinder. The use o f a charging cylinder elim inates the need for
scales, h o t w ater pails, etc.
The chief advantage o f this u n it is savings. A very definite
savings in refrigerant an d tim e can be o b tain ed by using this
u nit. Since the refrigerant is m etered in to the system by
volum e, th e correct am o u n t m ay be added to the system . This,
coupled w ith th e fact th a t the u n it rem ains " plum bed" at all
tim es an d thus elim inates loss o f refrigerant in purging o f lines
and hooking-up, com bines to enable the o p erato r to get full
use o f all refrigerant purchased.
All evacuation and charging equipm ent is h o o k ed together
in a com pact p ortable u n it (fig. 20). It brings air conditioning
service dow n to the basic problem o f hooking on tw o hoses,
an d m anipulating clearly labeled valves.
This will ten d to insure th a t the jo b will be done w ith o u t
skipping operations. As a result, you can expect to save tim e
and get higher quality w ork, less chance o f an over or
undercharge, or com eback.
The pum p m o u n t is such th a t the dealer m ay use his own
vacuum pum p. T he gauges an d m anifold are in com m on use.
Thus a current air conditioning dealer can use the equipm ent
on h an d an d avoid duplication.
V AC U U M
CONTROL
(3)
LO W
G AU G E LINE
F |9 2 0 -J -8 3 9 3 Charging statio n
A IR C O N D IT IO N IN G 1A-13
and m oisture should be
HIG H PRESSURE
CO NTROL (2)
FREON
CONTROL
(4 )
H IG H PRESSURE
G A U G E LINE
5 LB. CHA R G IN G
CYLINDER
LEAK
DETECTOR
FREON DRUM
CO NTROL VALVE
C H E V Y V A N S H O P M A N U A L