Valve Lifter Assemble; Test Valve Lifter Leak-Down Rate - Pontiac Grand Prix Service Manual

V-8
ENGINE
6-49
3. After varnish has dissolved or has been sufticiently
softened to permit removal by wiping, suspend 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 inju~y to hands (from solvent).
5.
Wipe out tank cover and place tray of parts on cover
in front of tank (Fig. 6-82). A'shop tow1 under tray
and clean paper on remainder of cover will enhance
cleanliness.
NOTE: Absolute cleanliness can be assured
if
each lifier
is
inspected and assembled a jer cleaning 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 UTZON: Do not use wire brush or sand paper, since
h m a g e to machined surface is likely.
7. Inspect lifter body. Both inner and outer surfaces 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 dam-
aged.
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 assemby. 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 highlight
slight grinder chatter marks and give the outer surface
of plunger a ridged or fluted appearance. T h i s
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.
VALVE LIFTER
-
ASSEMBLE
NOTE: All parts must be absolutely clean when
assembling a hydraulic 11Yer. 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 $ - o m cleaning
tank) should be used for each set of lifiers being
overhauled.
Fig 6-85 shows the relative position of component
parts of valve lifters. The recommended procedure for
assembly is given in the following steps.
1. Rinse plunger spring and ball retainer and position
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.
4. Invert plunger with parts assembled thus far and,
after rinsing lifter body, install body over spring and
plunger.
5. Place orifice feed plate in plunger.
6. Place lifter body on clean paper; rinse and install
push rod seat and retainer ring.
7. After lifter has been assembled, place in lifter box
and close lid to preserve cleaniness.
TEST VALVE LIFTER LEAK-DOWN RATE
After all lifters have been assembled, the leak-down
rate must be checked before they are installed in the
engine. Valve lifter leak-down tester J
5790
(Fig. 6-86)
is designed to test leak-down rate of lifters to
determine whether or not they are within specified
limits.
As
with previous service operations concerned
with lifters, cleanliness is important. The tester cup
and ram should be thoroughly cleaned, and testing
should be done in an area free of dust and dirt. The
testing procedure is described in the following steps:
1. Fill tester cup to approximately one inch from top
with special fluid which is available from your lifter
tester dealer.
NOTE: No other typefluid is recommended.
2. Swing weight
arm
up out of the way, raise ram, and
position lifter into boss in center of tester cup.
3. Adjust ram (with weight arm clear of ram) so that
the pointer is positioned on the set line (marked " 9 ' ) .
Tighten jam nut to maintain setting.
4. Operate lifter through full travel of plunger by
pumping weight
a r m
to fdl lifter with test fluid and