Galled threads on a rebuilt MECHANICAL FUEL PUMP?

ArVeeNiner · #1 03-15-2009, 07:40 PM

We'll try this post again. I had a big brain fart and substituted the word "carb" for "fuel pump" in the original post. Just to make this 100% correct, here is the post again but with the correct part referenced this time:

Has anybody ever found galled threads in an overhauled fuel pump? Is this common?

I got a rebuilt low pressure fuel pump from Aircraft Spruce and have been unable to start either the KB-000 or KB-090-T into it. I've tried them dry and with Fuel Lube and I can't get a single thread to catch. The fittings look perfect and in fact, I'm able to thread either end into an AN fitting no problem. It's kind of hard to tell but with a magnifying glass from a ways away it sure looks like at least one side of the pump has galled threads. I would have thought that the place that rebuilds the fuel pump also checks them so I'd imagine that they would have checked the threads.

jrs14855 · #2 03-15-2009, 08:13 PM

The AC style(whatever they call it these days) fuel pump is a straight thread. One option is a standard AN6 bulkhead fitting with an o ring and jam nut. If the standard fitting does not thread easily in place, send it back.

jrs14855 · #3 03-15-2009, 08:23 PM

The 90 degree fitting is AN833-6(steel) and the jam nut is AN924-6. Thread the nut onto the long end, then the o ring. Thread the long end into the fuel pump until it bottoms out, back it out one turn or less, slide the o ring against the pump and lock the jam nut. Thread is 9/16 18.