chevrolet truck Light Duty Truck 1994 Series, Repair Manual

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• Turn the driveshaft by hand to check for smooth
operation.
N O T IC E : B e c a r e f u l o f t w is t in g , s h e a r in g , o r
c o l la p s i n g t h e p i p e w h i l e i n s t a l l i n g in th e
p u m p .
7. Pickup screen and pipe (187) (if removed) (figure
52).
A. If the pickup screen and pipe assembly was
removed, it should be replaced with a new part.
Loss of press fit condition could result in an air
leak and loss of oil pressure.
B. Mount the .oil pump in a soft jawed vise.
C. Apply sealer to the end of the pipe.
D. Tap the pickup screen and pipe into place,
using J 21882 (5.0L and 5.7L engines), and a
hammer.
E. The pump screen must be parallel with the bot­
tom of the oil pan when installed.
8
. Oil pump driveshaft (178) and connector (179).
VALVE TR A IN COM PONENTS
PUSHRODS, ROCKER ARMS, BALLS, AND NUTS
I j j i Clean
• Parts in solvent. Blow dry with compressed air.
• Make sure the oil passages in the pushrods are
clear.
• Rocker arms and balls at their mating surfaces.
These surfaces should be smooth and free from
scoring or other damage.
• Rocker arm areas that contact the valve stems and
the sockets that contact the pushrods. These areas
should be smooth and free of damage and wear.
• Rocker arm nuts or bolts.
— The 5.0L and 5.7L engines use prevailing
torque nuts. At least 6.2 N-m (55 lbs. in.) of
torque should be required to thread the nuts
onto the rocker arm studs. If not, it is possible
that the nut(s) could back off during engine
operation causing a loss of lash and valve train
noise.
— The 7.4L engine uses a bolt to retain the rocker
arm, ball, and pushrod guide to the cylinder
head. Inspect rocker arm bolts for signs of
cracking at the bolt shoulder. Replace if neces­
sary.
• Check pushrods for bending. Roll the pushrod on a
flat surface to determine if it is bent. Replace if
necessary.
• Check ends of the pushrods for scoring or rough­
ness.
HYDRAULIC LIFTERS
Refer to SECTION
6
A.
CYLINDER HEAD
DISASSEMBLY
Disassemble (Figures 53, 54, and 55)
❖
40. Nut
253. Cap
41. Ball
254. Rotator
42. Rocker Arm
255. Shield
46. Cylinder Head
256. Spring
47. Gasket
with Damper
250. Rocker Arm Stud
257. Seal
251. Valve Keeper
258. Exhaust Valve
252. O-Ring Seal
259. Intake Valve
F9470
Tool Required:
J 8062 Valve Spring Compressor
1. Valve keepers (251).