Chevrolet 70 1969 Series, Shop Manual

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6V-53 DIESEL ENGINE 6C-7
necessary to permit removal of rod cover (tube)
(3, fig. 6).
11. Remove injector rack control tube and
bracket assembly.
12. Remove cylinder head bolts in gradual
stages to relieve spring pressure. When bolts have
been removed, lift cylinder head assembly off cyl­
inder block. Remove seals and gaskets from cyl­
inder liners and from recesses in block.
C A U T IO N : When resting the cylinder head
assembly on a bench, protect the cam follower
rollers and injector spray tips by resting the valve
side of the head on wooden blocks approximately
2 inches thick.
13. Remove cylinder head compression gas­
kets, oil seals, and water seals from block. Clean
the cylinder head surface which mates with cylin­
der block.
C Y L IN D E R H E A D IN S T A L L A T IO N (Fig. 8)
1. Inspect top of pistons to see that they are
clean and free from carbon deposits. Also check
and, if necessary, remove any deposits found in
groove and counterbores in top of cylinder block.
2. Install new cylinder head compression gas­
kets and seals as follows:
a. Install a new compression gasket on each
cylinder liner.
b. Place new seal rings in the counterbores
of water and oil holes in cylinder block.
c. Install a new oil seal in milled groove near
the outer edge of area covered by cylinder head.
N O T E : Used water seals, oil seals, and com­
pression gaskets should never be re-used.
3. Install guide studs (fig. 8) in head bolt holes
in cylinder block to insure positive location of
head without disturbing seals and gasket.
C A U T IO N : Compression gaskets and/or seals
which are jarred out of their proper location will
allow leaks and "blow-fcy" which will result in poor
performance and damage to engine.
4. Wipe bottom of cylinder head clean, then
lower cylinder head (fig. 8) onto guide studs and
down into contact with block. Lubricate threads and
pressure area of bolt heads with S .A .E . #30 engine
oil, then start all cylinder head bolts. Beginning at
camshaft side of cylinder head tighten head bolts
lightly to overcome tension of cam follower springs.
5. Tighten cylinder head bolts about one-half
turn in sequence shown in figure 9. Use torque
wrench for final tightening of cylinder head bolts.
Correct torque is 170 to 180 foot-pounds. Do not
tighten bolts beyond specified torque.
6. Cover oil drain holes in head to prevent
foreign objects from falling into holes. Install in­
jectors (if removed) referring to applicable por­
tion of EN G IN E F U E L S Y S T E M (SEC. 6M) of this
manual, for instructions. Check push rods to see
that each one is threaded completely through clevis,
Figure 8— Installing Cylinder Head on Engine
then tip rocker arms into position with valve
bridges squarely positioned at valve stems. Install
rocker arm shaft bracket bolts and tighten to 50
to 55 foot-pounds torque.
7. Set injector control tube and lever assem ­
bly in place and install attaching bolts finger tight.
Check injector control tube levers for engagement
with slots in injector control racks. Also, be sure
ends of rack control tube return spring are prop-
Figure 9— Cylinder Head Bolt Tightening Sequence
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SHOP MANUAL