Electric Fuel Pump Failure

Last night I was using the Facet fuel pump supplied by Van's (2001 aircraft 500 hours) to empty my left tank. I noticed that after pumping around 3 gallons the sound of the pump began to change (to more of a rattling sound) and it stopped pumping. After that I would have to shut the pump down, let it "cool" for a couple of minutes and then it would start flowing. Sometimes it would fail, but then start pumping again after a few seconds.

It is possible there is debris in it, I haven't removed it yet.

While it was pumping it would put out 22 GPH according to the Floscan. The pump is rated at 30 GPH.

My typical fuel pump test during the condition inspection has been to place the plane in a nose up attitude and determine the amount of fuel pumped by the electric pump in a 15 second time period (I only recently installed a flow guage). My new procedure will be to run the pump for about 7 minutes.

It was interesting that the failure mode was such that it would be transparent during normal pre-flight or inflight operations and would only reveal itself when the engine-driven pump had failed.

Just a data point.

John Allen

fliier said:

Last night I was using the Facet fuel pump supplied by Van's (2001 aircraft 500 hours) to empty my left tank.

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I'm not sure those pumps are built for that kind of fuel transfer. They are rated a MAX of 30 GPH. Running it that long with no restriction may have excellerated the problem? They are designed to maintain some pressure not pump at zero pressure.

Glad you found a weak pump, but wouldn't be easier to just take the quick drain out?

When the Faucet pump runs dry it goes from the semi-quiet sound to the much louder clanking sound (normal). The events as you describe would indicate an intermittent blockage prior to the pump or air instead of fuel to the pump. I'm not saying the pump is fine. It may or may not be. Do not limit your thoughts to the pump. Check from the pump all the way back to the fuel pickup.

Geico266 said:

I'm not sure those pumps are built for that kind of fuel transfer. They are rated a MAX of 30 GPH. Running it that long with no restriction may have excellerated the problem? They are designed to maintain some pressure not pump at zero pressure.

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THAT'S what I have found.. Call FACET and ask........ 1-800-456-8011 east coast.

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Oh I'm not sure. I'd be surprised if these pumps aren't rated for continuous duty, and I was running it at a flow rate well under its maximum. However the only point I was making that there was a failure mode that wasn't readily apparent using my existing testing methods and that I was changing my procedure. I posted in the safety forum because I thought there might be someone else out there who read it and went. . . Hmmmnnnn?

However, you bring up a point about removing the drain plug. I thought of that but couldn't figure out how to move those 5 gallon cans around while keeping my thumb over the hole. I also wasn't sure how much gas I was going to lose while trying to screw in a draincock (which I didn't have anyway). I had this vision of myself alone in the hangar at 10:00pm with my finger in the dyke looking like a Far Side cartoon. You'd think a guy who built his own airplane would be smarter than I am, but. . .

John Allen