Chevrolet Light Duty Truck 1973 Service Manual page 388

6 - 5 2 E N G IN E
will, in most cases, be caused by either insufficient
oil supply or improper adjustment.
4. Intermittent Clicking—Probable causes are:
a. A microscopic piece of dirt momentarily caught
between ball seat and check valve ball.
b. In rare cases, the ball itself may be out-of-round
or have a flat spot.
c. Improper adjustment.
In most cases where noise exists in one or more lifters all
lifter units should be removed, disassembled, cleaned in
a solvent, reassembled, and reinstalled in the engine. If
dirt, corrosion, carbon, etc. is shown to exist in one unit,
it more likely exists in all the units, thus it would only be
a matter of time before all lifters caused trouble.
Removal
1. Remove intake manifold as outlined.
2. Remove valve mechanism as outlined.
3. Remove valve lifters.
NOTE: Place valve lifters in a rack so that
they may be reinstalled in the same location.
Installation
1. Install valve lifters.
NOTE: Whenever new valve lifters are being
installed, coat foot of valve lifters with
"Molykote" or its equivalent.
2. Install intake manifold as outlined.
3. Install and adjust valve mechanism as
outlined.
Valve Stem Oil Seal and/or Valve Spring
Replacement
1. Remove rocker arm cover as outlined.
2. Remove spark plug, rocker arm and push rod on
the cylinder(s) to be serviced.
3. Install air line adapter Tool J-23590 to spark plug
port and apply compressed air to hold the valves in
place.
4. Using Tool J-5892 to compress the valve spring,
remove the valve locks, valve cap and valve spring
and damper (fig. 9V).
5. Remove the valve stem oil seal.
6. Assemble as follows:
SMALL V8 ENGINES
a. Set the valve spring and damper, valve shield
and valve cap in place. Compress the spring
with Tool J-5892 and install oil seal in the lower
groove of the stem, making sure the seal is flat
and not twisted.
NOTE: A light coat of oil on the seal will
help prevent twisting.
Fig. 8V—Valve Adjustment
b. Install the valve locks and release the compres­
sor tool making sure the locks seat properly in
the upper groove of the valve stem.
NOTE: Grease may be used to hold the locks
in place while releasing the compressor tool.
MARK IV V8 ENGINES
a. Install new valve stem oil seal (coated with oil)
in position over valve guide.
NOTE: Seal installation instructions are
supplied with each service kit. Install seal
following procedures outlined on the supplied
instruction sheet.
b. Set the valve spring and damper and valve cap
in place.
c. Compress the spring with Tool J-5892 and install
the valve locks then release the compressor tool,
making sure the locks seat properly in the
groove of the valve stem.
NOTE: Grease may be used to hold the locks
in place while releasing the compressor tool.
7. Install spark plug and torque to specifications.
8. Install and adjust valve mechanism as outlined.
Cylinder Head Assembly
Removal
1. Remove intake manifold as outlined.
2. Remove exhaust manifolds as outlined.
3. Remove valve mechanism as outlined.
4. Drain cylinder block of coolant.
LIGHT DUTY TRUCK SERVICE MANUAL