Valve Train Components; Hydraulic Lifters; Cylinder Head - GMC 1989 Light Duty Truck Repair Manual

1. S h a ft E xte n sio n
2. P um p B ody
3. D rive G ear and S h a ft
4. Id le r G ear
5. P um p C over
6. P ressure R e g u la to r Valve
7. P ressure R e g u la to r S p rin g
8. R e ta in in g Pin
9. S cre w s
10. P icku p S creen and Pipe
Figure 17— Oil Pump Components
• The pickup pipe is a press fit in the pump
body.
• Do not try to remove the screen from the pipe.
The pickup screen and pipe is serviced as an
assembly only.
Clean
All parts in clean so lve n t and blow dry w ith
compressed air.
I?
Inspect (Figure 17)
Pump body (2) and cover (5) for cracks or other
damage.
Gears (3 and 4) for wear.
Drive gear and shaft (3) for lack of fit in the pump
body (2).
Inside of the cover (5) for wear that would permit oil
to leak past the ends of the gears. The pump gears,
cover, and body are not serviced separately. If the
parts are damaged or worn, replace the entire oil
pump assembly.
Pickup screen and pipe (10) for damage to the
screen, pipe or relief grommet.
Pressure relief valve (6) for fit. The regulator valve
should slide freely in its bore without sticking or
binding.
Install or C onnect (Figure 17)
Tool Required:
J 21882, Pickup Tube and Screen Installer
1. Pressure regulator valve.
2. Spring.
3. Spring retaining pin.
4. Drive gear and shaft.
5. Idler gear.
• Index the marks made during disassembly.
6. Cover and screws.
$
Tighten
• Screws to 5.0 N-m (84 in. lbs.).
Turn the drive shaft by hand to check for smooth
operation.
N O TIC E: Be c a re fu l o f tw istin g , sh earin g or
collapsing the p ip e w hile installing the p um p.
7. Pickup screen and pipe (if removed) (figure 18).
• If the pickup screen and pipe assembly was
• Mount the oil pump in a soft jawed vise.
• Apply sealer to the end of the pipe.
• Tap the pickup screen and pipe into place,
• The pump screen must be parallel with the
8. Oil pump drive shaft and connector (1).

VALVE TRAIN COMPONENTS

B-09445
PUSHRODS, ROCKER ARMS, BALLS, AND NUTS
Clean
Parts in solvent. Blow dry with compressed air.
Make sure the oil passages in the pushrods are
clear.
Inspect
• Rocker arms and balls at their mating surfaces.
These surfaces should be smooth and free from
scoring or other damage.
• Rocker arm areas which contact the valve stems
and the sockets which contact the pushrods. These
areas should be smooth and free of damage and
wear.
• Rocker arm nuts.
• Pushrods for bending. Roll the pushrod on a flat
su rfa ce to d ete rm ine if it is bent. R eplace if
necessary.
• Pushrod ends for scoring or roughness.
Refer to GENERAL ENGINE MECHANICAL (SEC. 6A).
R em ove or D isconnect (Figures 19 and 20)
Tool Required:
1. Valve keepers (20).
• Compress the springs with J 8062 (figure 20).
• Remove the keepers.
• Remove J 8062.
2. Cap (21), shield (22), seal (24), and dam per (25),
and spring (26) (intake valve).
3. Rotator (28), shield (22), seal (24), and dam per (25),
and spring (26) (exhaust valve).
4. O-ring seals (23).
5. Valves (27 and 29).
• Place the valves in a rack so they can be
4.3 LITER V-6 6A3-13
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.
using J 21882 and a hammer.
bottom of the oil pan when installed.

HYDRAULIC LIFTERS

CYLINDER HEAD

J 8062, Valve Spring Compressor
returned to their original position at assembly.