How To: MFI Electric fuel pump overhaul

[kenikh]

This was too good to not share, now that I was able to find it again. From a 2003 Pelican posting:

The electric fuel pump on my 1970e was inop after sitting for 10 years. Based on the junk in the tank, I figured the pump was beyond repair. So the fun part comes, I get to take it apart to see how it runs, certainly can’t hurt it. Bottom line, after taking it apart replacing three orings, acquired from the local hardware store, and de-gunking, it now is humming and pumping the correct amount with no leaks.

Toughest part of the disassembly was undoing the “stakes” and prying the outer body from the top section. Haynes says these are not repairable, we’ll see. If any else attempts an overhaul consider it a last resort and be prepared to buy a replacement. Here are some pictures of the disassembled cleaned up unit

[kenikh]

A good comment from our recently departed friend:

Good show!

I would recommend using O-rings from an industrial bearing and seal supply house, rather than a hardware store ... less likely to have been sitting on the shelf 10 years, and the material is likely to be of higher quality! Viton would be the elastomer material of choice for fuel-handling O-rings.

[911quest]

One note on reassembling these pumps if you overtighten the four screws the pump won't spin.

[kenikh]

One note on reassembling these pumps if you overtighten the four screws the pump won't spin.

Do you have a torque spec?

[rick2]

Subscribed

[tfiv]

I've done this process before on old pumps, only to have the bearing seize after a few hours of running.

[kenikh]

Seems like a you can't lose trying, at least...