Fuel Pump Repair


Before you replace the fuel pump with a overhauled or new one, have a look what maybe wrong with it.

I the case below a disintegrated rubber seal made the pump seep oil.

First open up the dome of the pump as you should do every annual and verify it is not corroded. In this case we see remnants of disintegrated cork, but no corrosion.

After opening up the pump body we found this rubber seal at fault

New seal in - notice the clamping metal ring. This is where the main spring is resting

The underside of the diaphragm was affected by hot engine oil it appeared cracked unfortunately

This is how the new diaphragm goes into the pump careful push the stem through the seal and press down the spring at the same time.

The setup looks then like this - secure the pump halves.

On the underside guide the actuating lever through the stem's notch and secure with pin.

Add the small spring for the lever later and after safety wiring all is set.

Parts are available from Aircraft Spruce and others.

AF-6561 kit includes: fuel pump screen, TCM P/N 643913; cork cover gasket, TCM P/N 643915; bolt gasket P/N 643914, needed for AD 81-07-06

Diaphragm is available in FPA 28/29 rebuild kit from Then and Now Automotive. http://www.then-now-auto.com/product/buick-fpa-29/

Hartmut