1. Lap the injector body.
2. Tighten the nut to 55 to 65 lb ft (75-88 Nm) torque. Do not exceed the specified torque.
3. Replace the valve parts.
4. If the valve seat is chipped at the point of contact with the valve, lap the surface of the seat and the ID of
the hole. Mount tool J 7174 in a drill motor and place the valve seat on the pilot of the tool, using a small
amount of lapping compound on the lapping surface. Start the drill motor and apply enough pressure to bring
the seat to the point of lap. Check the point of lap contact after a few seconds. If the edge of the hole appears
sharp and clear, no further lapping is required. Excessive lapping at this point will increase the size of the hole
and lower the injector valve-opening pressure.
5. A worn or eroded valve seat may be lapped, but not excessively as this would reduce the thickness of the
part causing a deviation from the valve stackup dimension.
6. Replace the spring. Check the valve cage and valve stop for wear; replace them if necessary.
7. Replace the valve.
8. Replace the seal ring.
9. Install new body plugs.
10. Replace the filter gaskets and tighten the filter caps to 65 to 75 lb ft (88-102 Nm) torque.
11. Clean up the sealing surfaces or replace the filter caps, if necessary.
12. Disassemble the injector and clean all of the parts.