Pontiac tempest 1968 Service Manual page 265

6 - 4 8
1968 P O N T I A C SERVICE MANUAL
V A L V E L I F T E R — C L E A N AND INSPECT
Wash tank J 5821 Is recommended for cleaning
valve lifter parts. This tank consists of two cham­
bers, a tray and a cover. One chamber is for clean­
ing solvent and the other is for kerosene. Whenever
the tank is not being used (and when parts are soak­
ing), the cover should be closed.
1. Before placing tray of parts in cleaning solvent,
first immerse it in kerosene chamber to remove as
much engine oil as possible. (This reduces con­
tamination of solvent, thus prolonging its useful life.)
2. Submerge tray in cleaning solvent and allow to
soak for approximately one hour. More time may
be required depending on varnish condition and effec­
tiveness of solvent. Light agitation of tray in solvent
at 1 0 - 1 5 minute intervals will hasten cleaning action.
3. After varnish has dissolved or has been suffi­
ciently softened to permit removal by wiping, sus­
pend tray above solvent, utilizing hooks on tray
handles. Allow tray and parts to drain for a brief
period.
4 . Rinse tray of parts in kerosene chamber to cut
solvent and to avoid injury to hands (from solvent) .
Do Wipe out tank cover and place tray of parts on
cover in front of tank (Fig. 6 - 8 1 ) . A shop towel
under tray and clean paper on remainder of cover
will enhance cleanliness.
NOTE: Absolute cleanliness can be assured if
each lifter is inspected and assembled after clean-
ing before proceeding to the next lifter.
6 . Working on one lifter at a time and using clean,
lint-free cloths, thoroughly wipe ^ off lifter parts.
Clean plunger and external and internal surfaces of
body with hard wiping action. A bristle brush may
be used to clean internal surface of lifter body.
CA UTION: Do not use wire brush or sand paper,
since damage to machined surface is likely.
7. Inspect lifter body. Both inner and outer sur­
faces of lifter body should be inspected for scoring.
Lifter assembly should be replaced if body is roughly
scored, grooved, or galled. Inspect cam contact
surface on lower end of lifter body. Replace lifter
assembly if this surface is excessively worn, galled
or otherwise damaged.
8 . Inspect lifter plunger. Using magnifying glass,
inspect check ball seat for defects. Inspect outer
surface of plunger for scratches or scores. Small
score marks with rough, satiny finish will cause
plunger to seize when hot but operate normally when
cool. Defects in check ball seat or scores or
scratches on outer surface of plunger which may be
felt with fingernail are causes for replacing lifter
assembly. This rule does not apply to slight edge
which may sometimes be present where lower end
of plunger extends below the ground inner surface of
body. This edge is not detrimental unless it is sharp
or burred.
A blackened appearance is not a malfunctioning
condition. Sometimes discoloration serves to high­
light slight grinder chatter marks and give the outer
surface of plunger a ridged or fluted appearance.
This condition will not cause improper operation,
therefore, it may be disregarded.
9. Inspect push rod seat. Inspect push rod seat
for roughness and make sure that hole in center
is open.
10. Inspect valve lifter ball. Carefully examine
ball for nicks, imbedded material or other defects
which would prevent proper seating. Such defects
may cause intermittently noisy lifter operation. Also
inspect plunger face of ball retainer for excessive
wear.
V A L V E L I F T E R - A S S E M B L E
NOTE: All parts must be absolutely clean when
assembling a hydraulic lifter. Since lint and dust
may adhere to parts they should not be blown off
with air or wiped with cloths. All parts should be
rinsed in clean kerosene and assembled without
drying. A small container with clean kerosene
(separate from cleaning tank) should be used for
each set of lifters being overhauled.
Figure 6 - 8 4 shows the relative position of compo­
nent parts of valve lifters. The recommended pro­
cedure for assembly is given in the following steps.
1. Rinse plunger spring and ball retainer and po­
sition retainer in spring.
2. Rinse lifter ball and place in retainer.
3. Rinse plunger and place on retainer so that
seat on plunger mates with ball.
BALL CHECK
VALVE RETAINER
/
LIFTER
: - . . / PLUNGER
/
/
BODY 4"
PLUNGER
/
/
/
PLUNGER
1 PUSH ROD
SEAT
SPRING
/
/ s
BALL CHECK /
X /
BALL CHECK
VALVE SPRING
VALVE
ROCKER FEED /
METERING VALVE
R E T A I N E R - ^ .
RING
F i g . 6-84 Hydraulic V a l v e Lifter—Exploded View