Cummins N14 STC, Celect, Celect Plus – Service Manual 005-031   Fuel Pump Pulsation Damper

Remove the fuel inlet connection and pulsation damper or the filter head damper assembly.

Discard the rubber o-rings.

Remove the housing from the cover.

Remove the spring steel diaphragm and discard the o-rings.

Inspect the nylon washer and discard it if it is damaged.

Check for corrosion, wear, or cracks in the cover or the diaphragm. Replace the damaged parts.

To check the diaphragm for hidden cracks, drop it on a flat hard surface. It

must have a clear ring.

If it has a flat sound, replace the diaphragm.

Install new o-rings in the grooves and a new nylon washer.

Clean the diaphragm and coat it with clean engine oil.

Install the diaphragm in the cover and assemble the cover to the housing.

Tighten the capscrews.

Remove the two damper mounting capscrews.

Install the damper assembly with a new o-ring on the gear pump.

Tighten the capscrews.

NOTE: If a fuel filter and damper assembly are mounted on the gear pump, remove the four mounting capscrews.

Install the fuel inlet connection. Make sure not to let dirt enter the fuel pump.

Check for free rotation of the gear pump.