Fuel Pump: Testing and Inspection

1. Check outside of fuel pump for cracks and damage. Check for excessive wear between rocker arm and camshaft contact faces.

2. If damage is apparent or rocker arm wear is present, replace fuel pump.

3. Moisten valve seals by pouring a small amount of fuel into the pump.

4. Remove rocker arm spring. Measure force and play of the rocker arm by moving arm.

5. Move rocker arm to pump side and hold it in this position.

Inlet Valve Test:

6. Shut both the return pipe and outlet pipe. Allow rocker arm to return to original position.

7. When rocker arm is returned freeplay of rocker arm should increase. If freeplay does not increase, replace fuel pump.

Outlet Valve Test:

Diaphragm Test:

Oil Seal Test:

8. Shut inlet pipe, ensure rocker arm does not move. Repeat process for outlet, return and air pipes.

9. If rocker arm moves with either inlet, outlet, return or air pipe shut, replace fuel pump.

10. Reinstall spring. Ensure spring is properly seated.