Interesting Facet pump failure

[YellowJacket RV9]

One of the challenges I'm seeing in Phase 1 is that I don't have any baseline as to what "normal" sounds like. I know that my Facet fuel pump makes an awful racket when dry, but hums nicely when pumping fuel. Last flight, it seemed quieter to me, but still audible, and I didn't think much of it.

Today, I wanted to verify the accuracy of my fuel pressure sender as it occasionally reads slightly high (7-8.5 psi, O-320). To make a long story short, I found that the Facet pump was humming softly, but not pumping at all, and I confirmed this all the way back to the pump outlet itself, and on either tank, with no vent obstructions. Fuel flow has been excellent so far, and the initial test of the boost pump before first flight had confirmed very strong flow.

After checking all the connections and voltage, I removed the pump, ready to order a new one. Just to be sure, I decided to check the pump by itself outside of the plane. I blew through it and also shook it a little. At some point, I heard/felt a "click" inside the pump. I wired it to an extra 12V battery, and it worked as usual. Ran a fuel line into a jerry can and it pumped just as it should. So, I re-installed it in the plane, hit the switch, and all was normal again. Strong fuel flow and good pressure, and louder. Flew 1 hour today with no issues.

The more I think about it the more I suspect a small amount of debris may have clogged the pump and then dislodged as I shook it. I followed the plans religously with the fuel system so do not have a filter upstream of the pump. I plan on adding one now right after the fuel selector. Anybody else have any other possible culprits?

Chris

[petehowell]

Hi Chris,

I had one fail in a similar manner - I had to postmortem the pump to find the junk - this was before first flight - replacement has gone strong for ~1600 hrs.

Not sure if that helps - but confirms it happens.

[rightrudder]

Glad you got it sorted, Chris. Those pumps are pretty cheap; maybe you could pick up a spare, in which case you'd be multifaceted.

[gasman]

Originally Posted by YellowJacket RV9

One of the challenges I'm seeing in Phase 1 is that I don't have any baseline as to what "normal" sounds like. I know that my Facet fuel pump makes an awful racket when dry, but hums nicely when pumping fuel. Last flight, it seemed quieter to me, but still audible, and I didn't think much of it.

Today, I wanted to verify the accuracy of my fuel pressure sender as it occasionally reads slightly high (7-8.5 psi, O-320). To make a long story short, I found that the Facet pump was humming softly, but not pumping at all, and I confirmed this all the way back to the pump outlet itself, and on either tank, with no vent obstructions. Fuel flow has been excellent so far, and the initial test of the boost pump before first flight had confirmed very strong flow.

After checking all the connections and voltage, I removed the pump, ready to order a new one. Just to be sure, I decided to check the pump by itself outside of the plane. I blew through it and also shook it a little. At some point, I heard/felt a "click" inside the pump. I wired it to an extra 12V battery, and it worked as usual. Ran a fuel line into a jerry can and it pumped just as it should. So, I re-installed it in the plane, hit the switch, and all was normal again. Strong fuel flow and good pressure, and louder. Flew 1 hour today with no issues.

The more I think about it the more I suspect a small amount of debris may have clogged the pump and then dislodged as I shook it. I followed the plans religiously with the fuel system so do not have a filter upstream of the pump. I plan on adding one now right after the fuel selector. Anybody else have any other possible culprits?

Chris

But the pump installation instructions DO require it.

[YellowJacket RV9]

Originally Posted by gasman

But the pump installation instructions DO require it.

You got me. Filter on order.

Chris