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Facet fuel pump failure mode??

DaleB

Well Known Member
We’re just finishing up our CI, or trying to. 2011 RV-12 with 400 hours. We sealed up a slow leak in the fuel tank, so before trying to run the engine I put 5 gallons of fresh alcohol free mogas in the tank. Removed the drain from the gascolator and started running the pump to flush out the lines. It pumped about 2 gallons and suddenly stopped dead. Fuse is OK and there is power to the pump. The fans run with the master on. Only a minor drip of gas with the valve open and gascolator drain removed. I removed the baggage floor cover and gave it a couple of sharp taps with a screwdriver handle, no effect. The pump is not making any noise at all that I can hear...

Before I tear into this, what’s the most likely problem? Would a chunk of debris like Proseal that we missed with the vacuum do this? OF COURSE it has to happen on Friday afternoon...
 
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Dale---Check to make sure the pump is electrically grounded---you say you have power to the pump--verified?
If in fact the electrical is correct, pull the pump. Look for some debris, but you'll probably end up changing the pump. You might 'influence' the pump operation with a smack of a hammer, but then you probably will not want to fly with a boost pump thats being adolescent.

Tom
 
Dale -

This is not uncommon and has happened to a handful of other RV-12 owners. Before running out and replacing the pump, first try to rap on the top of the pump with a screwdriver handle or a small ball-peen hammer.

It has been reported after a few gentle but deliberate taps the fuel pump begins working again. Most likely yours will as well ... as it is very likely there is some debris hanging it up.

Some have strategically drilled a hole over the pump so a metal rod can be used to tap the pump without removing the access panel. I agree with Tom ... and would replace the pump or look deeper into why if the problem has become more than a one time event.

Hope this solves your issue.
Happy flying,
 
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I suggest using electrical contact cleaner to clean spade lugs. You might even crimp the female connector a little bit more closed. My Facet pump quit about 100 hours ago - cleaning electrical contact and a smart rap with screw driver handle fixed it.
 
Governor Valcik?s pump took a short vacay one time and a smack with a hammer did the trick. He got a month or so out of it. Can?t begin to remember all of the starters that I have overhauled with a hammer.
 
Sigh. Our condition inspection seems to be, a long last, finished save for a couple of deferred squawks. We made two test flights this afternoon.

Tapping on the fuel pump had no effect. I finally siphoned out the gas, stuck the nose wheel up on a step stool, and pulled the fuel pump. Oh what joy. Much smiling and happy thoughts in the hangar.

Once out I grabbed the jumper wires and hooked it directly to the battery. I could tell there was something going on -- a very faint sound, but nothign moving. A couple of sharp raps with the pump vertical (rather than horizontal, as mounted in the plane) and it started working. Hooked up some field expedient plastic tubing and spent half an an hour or so running gasoline between two gas cans with no issues at all. Got it mounted back in the plane (more joy and happiness) and all is well.

Maybe if I's swung the hammer fore-and-aft instead of from the top it would have saved me two hours of work. Maybe not, I don't know. We'll keep an eye on that pump, and I think we'll just plan to replace it at the next annual even if it's still working.

What made it stick? Lord only knows. It did sit empty and dry for two months. I would feel better about that answer if it had never even started, but it pumped about two gallons before stopping. I did notice, though, that afterward it seemed to be pumping a stronger stream than before.
 
What made it stick?

Dale-

Glad to hear you got the pump working after a couple of raps to the body.

Best guess is a small amount of crud jammed oscillating piston in the pump. Could have been a tiny piece of Proseal from the tank or a small piece of crud in the fuel ... best guess is the latter of the two. I occasionally see tiny hard chunks of crud stuck in the screen at the bottom of my Mr Funnel after refueling with Mogas from cans.

During my build I wanted to add a fuel filter between the tank and the fuel pump as Facet recommends .... and even bought a good one with a cleanable/replaceable stainless filter element. I just could not figure out a good place to install it between the pump and fuel tank that would also be easy to service.

Although quite expensive, had Flyboy Accessories offered this filter when I was building, I would have been very tempted to install it because it can be easily serviced from the belly of the airplane.
http://www.flyboyaccessories.com/product-p/72rr02.htm

Happy flying,
 
Back in the automotive days, we used to have to hit them every now and then. But we were on the ground and were stopped, not in the air------

Tom
 
. . . Best guess is a small amount of crud jammed oscillating piston in the pump. Could have been a tiny piece of Proseal from the tank or a small piece of crud in the fuel ... best guess is the latter of the two.
That type of debris should have been filtered at the gascolator. The only other origin where it could come from would be the fuel hose, feeding the pump itself. That could come from rubber shavings, at the hose ends, where the connection meets the barbed or banjo fittings.
That's why it is extremely important to make very 'clean' cuts on the hose ends and carefully fitting the hose ends over the metal fittings. Those metal fittings, especially barbed fittings (on some engines), tend to tear up the interior ends of hoses, thus, producing debris. The same could apply . . for debris in the carb float bowls.

This is a great tool for making clean and perfect cuts on hoses. The blade on this tool is razor sharp:

spin_prod_1155625312


https://www.amazon.com/Craftsman-9-...ywords=Craftsman+9-37301+3+7/8-Inch+Handi+Cut
 
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That type of debris should have been filtered at the gascolator. /QUOTE said:
Not on a 12 which has the pump near the gas tank and before the gasolator. It would have to pass through the tank finger screen but that is quite coarse.
 
Not to mention... there are no flexible hoses aft of the firewall. It's even possible an insect, cottonwood lint or something could have gotten into the fuel line while we had the tank out. Not to self: Any time the tank is out (hopefully never again) plug the lines.
 
That type of debris should have been filtered at the gascolator. /QUOTE said:
Not on a 12 which has the pump near the gas tank and before the gasolator. It would have to pass through the tank finger screen but that is quite coarse.
Scott,
When I said "pump," I was referring to the mechanical engine fuel pump, which is downstream from the gascolator.
If you guys are talking about the boost pump, then I stand corrected with my previous post.
 
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I found your problem.
http://www.facet-purolator.com/cube/

(Scroll down the page.)

Seriously, if you could find the installation instructions on the new 'improved' Facet web site, you'd see that they 'strongly recommend' a filter prior to the pump. You'd also see that the recommended installation orientation is the mounting tabs in a vertical plane, and the flow line in an upward 45 degree angle.

Obviously, almost none of us orient them that way and they still work. But trash is a pretty reliable way to make one quit working. IMO, it's a shame that the a/c kit companies haven't adopted automotive style in-tank 'sock' type filters. They're virtually clog proof, and self cleaning, for the life of the vehicle.
 
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