TM 5-4310-227-15
(4) Position the other bearing ball (5) in
c. Cleaning, Inspection, and Repair.
the bore in the top of the oil pump
(1) C l e a n all parts with an approved
body, then install the check ball re-
cleaning solvent, and dry thoroughly.
(2) Inspect all parts for cracks, breaks,
t a i n e r (6), the compression spring
(7), and the plunger (8).
and, signs of wear.
(5) Position the strainer (15) on the bot-
(3) Inspect the ball seat at the bottom of
tom of the oil pump body.
the seat bore for cracks, breaks, and
(6) After the oil pump has been assem-
worn condition. Replace a defective
call seat (b (5) above).
bled, and prior to installing it in the
(4) Inspect the bearing balls for rough-
ness and corrosion.
t h e pumping efficiency of the oil
(5) Apply a light film of engine oil to the
pump. Set the lower half of the oil
plunger; then insert the plunger into
pump in a container of clean engine
position in the oil pump body and
oil. Push the plunger down repeated-
measure the clearance between the
ly until a steady stream of oil sprays
plunger and the plunger bore. The
from the hole in the side of the spray
nozzel. This indicates that the oil
normal clearance should measure be-
tween 0.003 and 0.004 inch. Replace
pump is functioning properly.
e. Installation.
the plunger if the clearance is exces-
(1) Position the plunger pin (10) in the
sive. Replace the oil pump body if
worn.
rod bores in the two mounting flang-
(6) Inspect all applicable threaded com-
es inside the engine crankcase.
ponents for damaged threads.
(2) Install the push rod cap (9) firmly on
(7) Replace all defective oil pump parts.
the top of the camshaft end of the
(8) Inspect the plunger pin and cap for
plunger pin.
cracks, breaks, and signs of wear.
(3) Set the oil pump in the mounting po-
(9) Position the plunger pin in the two
sition in the bottom of the cylinder
bored mounting flanges inside the cyl-
and crankcase assembly and secure
the plunger pin moves freely and does
bolts (1) .
not bind.
(10) Examine the fit of the cap on the
plunger pin. The cap should set firm-
ly on the plunger pin,
(11) Replace a defective or excessively
b. Disassembly.
worn plunger pin or cap.
(1) To facilitate proper reassembly of the
d. Reassembly and Testing.
(1) Install the expansion plug (11) in the
ing bracket (11), scribe-mark the in-
top of the spray nozzle on the oil
let and outlet sides of the head.
pump body (3). Carefully make sev-
(2) Remove the screw and lockwasher as-
eral small notches around the edge of
semblies (14) and remove the head
the plug with a sharp pointed punch
(12).
to secure the plug in position.
(3) Turn head over. Remove the screw
(2) Using an arbor press, install the ball
(15) that secures the valve assemblies
seat (4) in the seat bore in the oil
(3, 5, 6, and 10) in the head. (12),
pump body.
note the location of each part, and
(3) Position the bearing ball (5) in the
r e m o v e the valve plate and seats
bore inside the oil pump body. Insert
( 1 0 ) , springs (3), valves (6), and
the outlet compression spring (13)
valve gasket (5). Discard springs (3),
into the same hole and secure with the
valves (6), and valve gasket (5).
pipe plug (12).
(4) Remove rocker arm spring (13).