Chevrolet 70 1969 Series, Руководство по ремонту

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C A B A N D BO DY M O U N T IN G S 1-77
2. Unthread burner head assembly from burner
tube. This will expose orifice block which is in­
serted into the end of the tube.
3. Remove orifice block from tube.
4. Reverse orifice block and replace against
burner tube; thread burner head onto burner tube
(hand tight), then open valve quickly, admitting
several short blasts.
5. To reassemble: Unthread burner head, in­
sert orifice block into burner tube, and thread
burner head onto burner tube with a wrench to
form a gas-tight joint.
Replacement parts can be obtained from Kent -
Moore Corp., Detroit, Michigan.
C H E C K IN G F O R R E F R IG E R A N T L E A K S
After the leak detector flame is adjusted,
check for refrigerant leaks in an area having a
minimum amount of air flow in the following man­
ner (see fig. 15):
Explore for leaks by moving end of sampling
tube around all connections and points where a
leak may be. Check around bottom of connections,
since Refrigerant-12 is heavier than air and will,
therefore, be more apparent at bottom of fitting.
The color of the flame will turn to a yellow-
green when a small leak is detected. Large leaks
will be indicated by a change in color to brilliant
blue or purple. When the suction hose is moved
away from the leak the flame will clear to an al­
most colorless pale blue again.
C A U T IO N : Do not breathe the fumes
and black smoke that are produced if
the leak is a big one. They are poison­
ous! Any time an open flame is used
near a vehicle there is a certain amount
of danger. Although the torch flame is
small and well protected, it is recom­
mended that fire extinguisher be close
at hand for any emergency that might
arise.____________________________________ __
LIQUID-TYPE L E A K D E T E C T O R S
There are a number of fittings and places
throughout the air conditioning unit where a liquid
leak detector solution may be used to pinpoint leaks.
By merely applying solution to the area with the
swab that is usually attached to the bottle cap, bub­
bles will form within seconds if there is a leak.
For confined areas, such as sections of the
evaporator and condenser, the torch-type detector
is the only practical kind which should be used for
determining leaks.
E L E C T R O N IC L E A K D E T E C T O R
An electronic leak detector for detecting re­
frigerant leaks is also available. Instructions for
operation of this type detector are supplied with the
unit.
REPLACING COMPRESSOR
The compressor removed must be closed im ­
mediately. See lower View of figure 16 which shows
a closure plate whi'ih can be improvised and in­
stalled as shown.
If the system has been or can be operated for
more than two minutes, circulation of oil from the
compressor to other components of the system will
require adjustment of the oil charge in the new
compressor as explained previously, under "R e ­
placing Components Other Than Compressor."
After draining and measuring the oil from the
crankcase, the amount that has migrated to other
parts of the system can be determined by subtract­
ing the amount drained from the original oil charge
of 11 fluid ozs. The amount of oil equal to this loss
shall be drained from the new compressor assem­
bly before it is installed.
R E P L A C IN G A N O P E R A B L E C O M P R E S S O R
After idling compressor (on vehicle) to be re­
placed for 10 minutes at 1500-2000 engine rpm, at
maximum refrigeration and blower at high speed:
D O N O T add any more oil to the compressor than
is necessary or maximum cooling will be reduced.
1. Compressor replaced with service com­
pressor assembly.
a. Remove compressor and place in a hori­
zontal position with drain plug downward, drain
compressor, measure quantity of oil drained and
then discard it.
b. Drain oil from replacement compressor and
save it.
c. (1) If amount of oil drained in ’^"previous­
ly is more than 4 ozs., place into the
new compressor the same amount of oil
drained from the replaced compressor.
(2) If amount of oil drained in "a ” previous­
ly is less than 4 ozs., place 6 ozs. of
oil in the replacement compressor.
d. Install compressor.
2. Compressor replaced with a field repaired
(overhauled) compressor.
a. Proceed as in step 1 previously, and then
add one extra oz. of oil. (More oil is retained in a
drained compressor than one that has been rebuilt.)
R E P L A C IN G A N IN O P E R A T IV E C O M P R E S S O R
In the case when it is not possible to idle the
compressor to be replaced to effect oil return to
it the following will apply. D O N O T add any more
oil than is necessary as maximum cooling will be
reduced.
1. Remove compressor from vehicle, drain
and measure the oil.
2. If amount drained in step 1 above is more
than 1-1/2 fluid ozs., subtract this amount drained
CHEVROLET SERIES 70 -80 H EAVY DUTY TRUCK SH O P M A N U A L