16-21.PISTON PUMP - REPAIR (Contd)
f. Install bearing spacer (33) at
one pintle end.
g. Install new O-ring (32) against
spacer and into groove at one
h. Install a 0.010 inch shim under
pintle cover (29) at one pintle
i. Install four pintle cover screws
(28) into pintle cover installed
in step h above, and tighten
screws to 175-185 lb. in.
j. Place housing (6) on its side so
other end of pintle is facing up.
Install bearing spacer (33).
k. Turn yoke (26) back and forth to
seat bearings (31) in bearing
5. INSTALL CORRECT PINTLE SHIMS (27).
a. With spacer (33) fully installed
against bearing race (30), measure
height of spacer with respect to
the housing pintle face using a
micrometer. Take measurements in
two places, 180 degrees apart.
b. Average the two readings taken in
step a above to obtain a nominal
A 0.007 - 0.009 inch preload is required
on the pintle bearings.
c. Determine the number of shims
required to obtain a preload
between 0.007 and 0.009 inches by
subtracting the nominal preload
(0.008) from the calculated
nominal valve (step b).