Chevrolet 70 1969 Series, Shop Manual

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POWER BRAKE 5-41
Figure 16 — V ie w o f O ffse t C o n n e c tin g Rod (L o n g Boss)
valve into cylinder head. T ap guard firmly into place,
then stake in place at four points (see fig. 17). Install
the other inlet valve and valve guard in the sam e m a n ­
ner. After both valves are installed, turn cylinder head
over and check operation of valves. Using one of the
inlet valve plungers w ithout spring, insert plunger
down through cylinder head onto inlet valve. Press
inlet valve down against valve guard, then m ake sure
inlet valve springs back up when released.
3. Install pipe plugs removed at disassembly.
4. O n air-cooled model install air inlet elbow (where
used) and air strainer.
CYLINDER HEAD INSTALLATION
Place new cylinder head gasket over studs on top of
cylinder block so cut-out portion of large holes will be ad ­
jacent to discharge valve seats when cylinder head is in­
stalled. Install cylinder head over studs with m arks m ade
prior to disassembly aligned, or with depression at side of
head over short stud in block. Install nuts on studs and
tighten to 16 to 17 foot-pounds torque.
UNLOADER ASSEMBLY
INSTALLATION
1. Install two inlet valve plungers and plunger springs.
Refer to Figure 18.
2. Position unloader assembly on cylinder head and se­
cure with two bolts and lock washers.
G O V ERN O R ASSEMBLY
INSTALLATION
1. Install the governor assembly and bracket loosely on
cylinder head with studs.
2. C onnect tube assembly to unloader and governor,
then final tighten governor m ounting stud nuts. M ake
sure that tube connections are tight.
A
Inlet Valve Guard
V I i
Figure 1 7 — S t a k in g Inlet V a lv e G u a r d in C y lin d e r H e a d
NOTE: If pulley is removed during the over­
haul, it must be replaced by the same size pul­
ley. A different size pulley will require a differ­
ent size drive belt. Also, the capacity of com­
pressor will change in relation to engine rpm.
TESTING REBUILT AIR CO M PRESSOR
NOTE: This procedure is described for making
test with shop equipment, but can be readily
adapted to testing in vehicle.
C onnect an oil supply line having at least 15 pounds
pressure to crankshaft rear bearing cap; provisions must
be m ade for unrestricted draining of oil from crankcase
during test. If tests are being m ade in dusty atm osphere,
connect a suitable air strainer to com pressor air inlet
opening.
RUN-IN TEST
W ith com pressor connected to a source of power (at
least 1 - 1 / 2 horsepower) to run it at 1250 rpm , run com ­
pressor for one-half hour with discharge port open to at­
mosphere. Check during this test for oil leaks, overheat­
ing, and excessive noise.
OIL PASSING TEST
Oil passing test is m ade by running air com pressor for
one-half hour at 1250 rpm, pum ping against 50 pounds
air pressure, with an oil trap connected into discharge
line. Oil passed during this test m ust not exceed two cubic
centimeters.
EFFICIENCY TEST
Efficiency test is m ade by running com pressor for one-
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SH O P M A N UA L