Disassembly, Cleaning, Inspection And Reassembly; Hydraulic Valve Tappet Leak-Down Test; Timing Case Cover; Hydraulic Valve Tappet Leak-Down Rate Tester - Jeep J-10 Series 1982 Technical & Service Manual

1B-40 ENGINES
Disassembly, Cleaning, Inspection and Reassembly
NOTE: Retain tappet components in the same order as
removed.
(1) Release lockring and remove plunger cap, me
tering disc, plunger, check valve assembly and plunger
return spring from tappet body (fig. 1B-56).
(2) Clean components in cleaning solvent to remove
all varnish and gum deposits.
(3) Inspect for evidence of scuffing on side and face
of tappet body.
(4) Inspect each tappet face for concave wear by
laying straightedge across face. If face is concave, corre
sponding lobe on camshaft is also worn, and replace
ment of camshaft and tappet(s) is necessary.
(5) Install plunger return spring, check valve as
sembly, plunger, metering disc and plunger cap in tap
pet body (fig. 1B-56).
(6) Compress plunger assembly using push rod on
plunger cap, and install lockring.
Hydraulic Valve Tappet Leak-Down Test
After cleaning, inspection and reassembly, leak-down
test each tappet to ensure zero-lash operation. Figure
1B-59 illustrates tool J-5790, which can be used to accu
rately test tappet leak-down rate.
TOOL
J-5790
AJ41891
Fig. 1B-59 Hydraulic Valve Tappet Leak-Down Rate Tester
(1) Swing weighted arm of tester away from ram of
tester.
(2) Place 0.312- to 0.313-inch (7.925 to 7.950 mm)
diameter ball bearing on tappet plunger cap.
(3) Lift ram and place tappet with ball bearing in
side tester cup.
(4) Lower ram, then adjust nose of ram until it
contacts ball bearing. Do not tighten hex nut on ram.
(5) Fill tester cup with Valve Tappet Test Oil J-
5268, or equivalent, until tappet is completely covered.
(6) Swing weighted arm onto ram and pump up and
down on tappet to remove air. When air bubbles cease,
swing weighted arm away and allow plunger to rise to
normal position.
(7) Adjust nose of ram to align pointer with SET
mark on scale of tester and tighten hex nut.
(8) Slowly swing weighted arm onto ram. Rotate
cup by turning handle at base of tester clockwise one
revolution every two seconds.
(9) Time leak-down interval from instant pointer
aligns with START mark on scale until pointer aligns
with 0.125 mark. Acceptable tappet will require 20 to
110 seconds to leak-down. Discard tappets that have
leak-down interval outside this range.
NOTE: Do not charge the tappet assemblies with en
gine oil. They will charge themselves within 3 to 8 min
utes of engine operation.
Installation
(1) Dip each tappet assembly in Jeep Engine Oil
Supplement (EOS), or equivalent.
(2) Use Hydraulic Valve Tappet Remover and In
staller Tool J-21884 to install each tappet in same bore
from where it was removed.
(3) Install cylinder head and replacement gasket
and tighten screws. Refer to Cylinder Head Installation
for tightening sequence.
(4) Install push rods in same order as removed.
(5) Install rocker arms and bridge and pivot assem
blies. Loosely install capscrews at each bridge. Tighten
capscrews alternately, one turn at a time, to avoid dam
aging or breaking bridge.
(6) Pour remaining EOS over entire valve train.
NOTE: The EOS must remain in the engine for at least
1,000 miles (1 607 km) but need not be drained until the
next scheduled oil change.
(7) Install cylinder head cover. Refer to Cylinder
Head Cover for procedure.
(8) Install coolant.
TIMING CASE COVER
The timing case cover is provided with a seal and oil
slinger to prevent oil leakage at the vibration damper
hub (fig. 1B-60). A socket is attached in the cover for the
use of a magnetic timing probe. A graduated timing
degree scale is located on the cover for standard ignition
timing.