Chevrolet 70 1969 Series, Руководство по ремонту

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E N G IN E 6-23
TPM-6681
Figure 3 4 — V a lv e Rocker A rm A sse m b ly
cant on valve stems at assembly.
1. Plaee rotator (3) in counterbore at each valve guide as
shown. Spring pilot on each rotator must be on top.
2. Place spring (4) on rotator, then place valves in re­
spective guides.
3. Place spring cap (5) and exhaust valve spring (4) in
place on rotator (3) with close-coiled end of spring
toward cylinder head. Compress spring and install
two valve keys (6). Be sure keys seat in groove in
valve stem.
4. With spring cap (5) on intake valve spring, compress
spring sufficiently to permit installation of oil seal (7)
in groove in intake valve stem. Install seal (7) and two
keys (6), then release spring. Be sure keys seat in
grooves in valve stems.
VALVE ROCKER ARMS (Fig. 34)
1. Wash rocker arms, shaft, and bracket assemblies in
solvent. Oil holes in rocker arm s must not be clogged.
2. Examine threads on adjusting screw which must be in
good condition.
3. If rocker arms are loose on shaft, disassemble and
measure bore through rocker arms which must be as
specified in Figure 34.
4. Examine shaft for evidence of wear. Replace worn
parts when assembling.
IMPORTANT: When installing new adjusting
screws in rocker arms, lubricate screw threads
and threads in rocker arm with engine oil prior
to assembly.
WATER PUMP OVERHAUL
GEN ERAL
A heavy duty water pu m p (fig. 35) is used on all stan­
dard 401M and 478M engines.
Overhaul procedure for each type of water pum p is
given separately under respective headings.
W ATER P U M P
(FOR 4 0 1 M A N D 4 7 8 M E N G IN ES)
Key numbers in text refer to Figure 35.
DISASSEMBLY
1. Support hub (1) on press and press the shaft out of
hub.
2. Insert spacers between impeller (5) and pump body
(6) to support impeller while pressing shaft and bear­
ing assembly (2) out of impeller and pum p body. S u p ­
port body on press bed, then with arbor press and
suitable driver, press on impeller end of shaft and re­
move shaft and bearing assembly (2).
3. Drive seal (3) out of pump body. If seal seat (4) in
impeller is not in good condition, use a thin blade to
pry the seal seat out of impeller. Thoroughly clean
the impeller counterbore.
4. Clean and inspect water pum p components. In case
defective parts are found, a repair kit consisting of
shaft and bearing assembly, seal, and gasket is avail­
able.
ASSEMBLING WATER PUMP
1. Be sure slinger (7) is in plaee on shaft. If necessary to
install new slinger press slinger against shaft shoulder
as shown.
2. Apply sealer in seal cavity in body, then press new'
seal assembly (3) squarely into place with seal flange
seated against body.
3. Support pum p body (6) solidly on press bed. then
press on shaft bearing outer housing to install shaft
and bearing assembly in body. Bearing housing must
bottom in pu m p body.
4. Place neoprene seal on ceramic seat (4), then install
seat in the recess in impeller with neoprene seal bot­
tomed in counterbore.
5. Support front end of pum p shaft and press impeller
onto rear end of shaft.
a. The impeller (5) must be positioned so rear face of
impeller hub is 1.520 inches from mounting flange
surface on pum p body (fig. 35).
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK SH O P M A N U A L