Unit Inspection

1. Check the outside of the fuel pump for cracks and other damage.
- The fuel pump must be replaced if cracks or other damage are present.

2. Check for excessive wear between the rocker arm and the camshaft contact faces.
- The fuel pump must be replaced if there is excessive wear.

3. The following measures must be taken prior to the inspection of the fuel pump interior.
- Moisten the valve seals by pouring a small amount of fuel into the fuel pump.
- Measure rocker arm force and play by moving the arm after opening the four pipes.
- Remove the spring to inspect. Rocker arm force and play must be measured before inspection.





4. Check the inlet valve.
- Move the rocker arm to the pump side and hold it in this position.
- Shut both the return pipe and the outlet pipe.
- Allow the rocker arm to return to its original position.
- When the rocker arm has returned to its original position, there should show a marked increase in the amount of play.
- If the amount of play does not increase, the fuel pump must be replaced.





5. Check the outlet valve.
- The rocker arm must not move when the inlet pipe is closed.

Note: Do not apply excessive force to the rocker arm.

- The fuel pump must be replaced if there is excessive play.





6. Check the diaphragm.
- The rocker arm must not move when the inlet, the outlet, and the return pipes are shut

Note: Do not apply excessive force to the rocker arm.

- The fuel pump must be replaced if the rocker arm moves.





7. Check the oil seal.
- The rocker arm must not move when the air pipe is shut
- The fuel pump must be replaced if the rocker arm moves.

Note: If the spring has been removed from the fuel pump, it must be replaced in its original position.