(c) Delivery valve opening pressure is
300-600 psi. Delivery valve must hold 275 psi for 30
seconds. Remove delivery valve assembly from test
fixture. The delivery valve spring (1) must be free of nicks
or wear (flat spots). Replace fuel injection pump if springs
are nicked or worn.
Lapping compound must not come in contact
with the relief piston during the lapping
operation, and all lapping compound must be
removed before installing the delivery valve
assembly into the hydraulic head.
(d) If the delivery valve assembly is leaky,
the delivery valve seat may be lapped to its corresponding
seat in the delivery valve body with a small quantity of
suitable lapping compound.
grooved, ridged, scored, or exhibits an uneven wear
pattern, it must be replaced.
(3) Inspect the tappet (20) for possible wear at
the contact areas. The primary contact areas are the
0.002-inch. The tappet thickness measured between the
plunger button contact surface and the cam contact area
must be 0.207-inch or larger.
washed in a cleaning solvent. Check all the screw threads
Always check to ensure that all external
in the housing; damaged threads can be repaired using
connections are tight and that the nozzle test
stand is in good order.
(5) Examine the pump housing for cracks or
other damage which will cause oil leakage. Replace
(b) Attach test fixture TSE 76226 (3) to a
manually operated Nozzle Test Stand.
complete pump if pump housing is damaged.