Valve Train Components; Cylinder Head - GMC 1990 Light Truck Repair Manual

Drive gear and shaft (128) for looseness in the pump
body (77).
Inside of the cover (82) for wear that would permit oil
to leak past the ends of the gears.
The pump gears and body are not serviced
separately.
Pressure relief valve (85) for fit. The regulator valve
should slide freely in its bore without sticking or
binding.
*
Assemble (Figures 32 and 33)
Tool Required:
J 21882 Oil Suction Pipe Installer
1. Pressure relief valve (85).
2. Spring (80).
3. Spring retaining pin (79).
4. Drive gear and shaft (128).
5. Idler gear (127) in the pump body (77) with the
smooth side of the gear toward the pump cover
opening. Index the marks made during disassembly.
6. Gasket (83).
7. Cover (82) and screws (81).
Tighten
• Screws to 14 N m (10 ft. lbs.).
• Turn the driveshaft by hand to check for smooth
operation.
NOTICE: Be careful of twisting, shearing or
collapsing the pipe while installing in the pump.
8. Pick-up screen and pipe (129) (if removed).
• 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.
• 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,
using tool J 21882 and a hammer.
• The pump screen must be parallel with the
bottom of the oil pan when installed.
2.5 LITER L4 ENGINE 6A1-19

VALVE TRAIN COMPONENTS

PUSHRODS, PUSHROD GUIDES,
ROCKER ARMS AND BALLS
i g i Clean
Parts in solvent. Blow dry with compressed air.
Make sure the oil passages in the pushrods are
clear.
] ? Inspect (Figures 3 and 10)
— Rocker arms (33) and balls (32) at their mating
surfaces. These surfaces should be smooth and
free from scoring or other damage.
— Rocker arm (33) areas which contact the valve
stems, and the sockets which contact the pushrods
(47). These areas should be smooth and free of
damage and wear.
— Pushrods (47) for bending. Roll the pushrod on a flat
surface to determine if it is bent. Replace if
necessary.
— Ends of the pushrods (47) for scoring or roughness.
VALVE LIFTERS
For inform ation regarding valve lifters refer to
GENERAL ENGINE MECHANICAL (SEC. 6A) of this
manual.

CYLINDER HEAD

Information regarding cylinder head disasembly and
assem bly is covered under th is procedure. For
information regarding cleaning and inspection, and
measuring of the cylinder head as well as valve
measuring and grinding and valve guide reconditioning,
refer to GENERAL ENGINE MECHANICAL (SEC. 6A) in
this manual.