Chevrolet 10 Series 1970 Service Manual page 45

• F le x ib le hose lin es should be inspected at lea st once
a y e a r fo r leaks o r b rittlen ess.
leaking they should
• U se only new lines that have been sealed during
storing.
• When disconnecting any fittin g in the re fr ig e r a tio n
system , the system must fir s t be discharged of all
re frig e ra n t. H ow ever, p roceed v e r y cautiously r e ­
g a rd le s s of gauge readings.
ing fa ce and hands away so that no injury can occur
if th ere happens to be liquid re frig e ra n t in the line.
If p re s s u re is noticed when fittin g is loosened, allow
it to b leed o ff v e r y slow ly.
CA UTIO N: Alw ays w ear safety goggles when
opening r e frig e ra n t lines.
• In the event any line is opened in atm osphere, it
should be im m ed iately capped to prevent entrance
of m oisture and dirt.
• The use of the p rop er wrenches when making con­
nections on "O " ring fittin gs is im portant.
of im p rop er wrenches may damage the connection.
The opposing fittin g should always be backed up with
a wrench to preven t d istortion of connecting lin es or
components. When connecting the fle x ib le hose con­
nections it is im portant that the swaged fittin g and
the fla r e nut, as w e ll as the coupling to which it is
attached, be held at the sam e tim e using three d if­
fe re n t wrenches to preven t turning the fittin g and
dam aging the ground seat.
• " O " rin gs and seats must be in p e rfe c t condition.
The sligh test burr o r p iece of d irt may cause a leak.
• Sealing beads on hose clamp connections must be
fr e e o f nicks and scratch es to assure a p e rfe c t seal.
M A IN T A IN IN G CHEMICAL STABILITY IN THE
REFRIGERATION SYSTEM
The m etal internal p arts of the r e frig e ra tio n system
and the re frig e ra n t and o il contained in the system are
design ed to rem ain in a state o f chem ical stability as
long as pure R-12 and uncontaminated re frig e ra tio n o il
is used in the system .
H ow ever, when abnorm al amounts of foreig n m a teria ls,
such as d irt, a ir o r m oistu re are allowed to enter the
s yste m , the chem ical stab ility may be upset.
c e le ra te d by heat, these contaminants may fo rm acids
and sludge and eventually cause the breakdown of com ­
ponents within the system .
m ay affect the tem p era tu re-p ressu re relationship of R-12,
resu ltin g in im p ro p er operating tem perature and p r e s ­
s u res and decreased e ffic ien c y of the system .
The fo llo w in g gen eral p ra ctic es should be o b served to
in su re chem ical stab ility in the system .
• W henever it becom es
re frig e ra n t o r gauge line, it should be im m ediately
capped. Capping the tubing w ill also prevent d irt and
fo re ig n m atter fro m entering.
• T o o ls should be kept clean and dry.
cludes the gauge set and replacem ent parts.
• When adding o il, the container should be exception­
a lly clean and dry due to the fact that the r e fr ig e r a ­
tion o il in the container is as m o is tu re -fre e as it is
p ossible to make it.
sorb any m oisture with which it com es in contact.
F o r this sam e reason the o il container should not be
If found b rittle o r
be rep laced with new lines.
Open v e r y slow ly, keep­
The use
When ac­
In addition, contaminants
n ecessary to disconnect a
This also in­
T h e re fo re , it w ill quickly ab­
HEATER AND AIR CONDITIONING 1A-15
capped im m ed ia tely a fter use.
• When it is n ecessary to open a system , have e v e r y ­
thing you w ill need ready and handy so that as little
tim e as p ossible w ill be requ ired to p erfo rm the
operation. Don't lea ve the system open any lon ger
than is necessary.
• F in ally, a fter the operation has been com pleted and
the system sealed again, a ir and m oistu re should be
evacuated fro m the system b efo re recharging.
J -8 3 9 3 C H A R G IN G STATION
The J-8393 Charging Station is a portable assem bly of
a vacuum pump, r e frig e ra n t supply, gauges, va lve s, and
m ost im portant, a fiv e (5) pound m eterin g re frig e ra n t
charging cylin der. The use of a charging cylin der e lim ­
inates the need fo r sca les, hot w ater p ails, etc.
The chief advantage of this unit is savings.
d efin ite savings in re frig e ra n t and tim e can be obtained
by using this unit. Since the refrig era n t is m etered into
the system by volum e, the c o rre c t amount may be added
to the system . Th is, coupled with the fact that the unit
rem a in s "plum bed" at a ll tim es and thus elim in ates loss
o f re frig e ra n t in purging of lines and hooking-up, com ­
bines to enable the op era to r to get fu ll use o f all r e ­
frig e r a n t purchased.
A ll evacuation and charging equipment is hooked to­
g eth er in a com pact portable unit (fig. 24).
conditioning s e rv ic e down to the basic p roblem of hooking
on two hoses, and manipulating c le a rly labeled va lves.
This w ill tend to insure that the job w ill be done without
skipping operations. As a result, you can expect to save
tim e and get higher quality work, le s s chance o f an o v er
o r undercharge, o r comeback.
LO W PRESSURE
CO NTROL (1)
V A C U U M
CONTROL
(3)
LO W
G A U G E LINE
OIL
INJECTOR
J-8393
F ig . 2 4 —
A v e ry
It brin gs a ir
HIG H PRESSURE
CONTROL (2)
FREON
CONTROL
4
( )
H IG H PRESSURE
G A U G E LINE
5 LB. C H A R G IN G
CYLINDER
LEAK
DETECTOR
FREON DRUM
CO NTROL VALVE
C ha rg in g S ta tio n
CHEVROLET TRUCK SERVICE MANUAL