AN adapter fitting question

[dilley340]

I'm having trouble with my AN NPT fittings seating into my electric fuel pump and regulator. I can only get 1-2 thread maximum engagement using two different manufacturer's (Aeroquip & Russell) fittings. 3/8" NPT to be exact. I have ran a 3/8" NPT tap through the pumps and regulators and they seem fine. My question is there a trick to prepping the threads before assembly? Should I remove the anodizing on the fitting threads to help get a better engagement? I'm worried I won't get a good seal when I add the teflon tape.

BTW, what fittings do you guys use?

 

[1970Duster]

Are you sure they are the same thread count?

 

[stumper]

If the pump uses 3/8 npt, a 3/8 npt male end from any manufacturer should fit right in with no issue. You may want to consider using some good pipe dope instead of the teflon though. Gas eats teflon in short order. Dope the threads up and run it on in. It won't screw in by hand very far if that's what you are trying to do, you'll need to turn it in with a wrench.

 

[67Dart273]

You may have the wrong adaptors. Do the ends which are supposed to be pipe appear tapered? Round up a caliper and thread gauge, or run down to a fastener store that is likely to have one

Some adapters may be what some call "o ring boss" which is a straight thread just like AN fittings, except instead of a flare, they are "flat" on the end, and use an o-ring seal on the face.

 

[crackedback]

which pump.

Some pumps use a -8 thread, like the mallory 250.

 

[67Dart273]

which pump.

Some pumps use a -8 thread, like the mallory 250.

Crack what would we do without your mind around here?

 

[crackedback]

Crack what would we do without your mind around here?

You answered it above as well.

Best thing to do is look at the instruction for whichever pump it is ans see if it designates input/output thread.

something like this fitting written about -8 threads on both sides and an O-ring for sealing
http://www.summitracing.com/parts/SUM-220165B/?rtype=10

IIRC. A fitting that uses an AN-8 is a 3/4-16. So if you have a 3/4" fine thread bolt and it runs in the opening, you know it's a -8 o-ring fitting.

 

[fstfish66]

do you have too much tape on the fitting ? are the threads on the fitting buggered up,,,,yes i said buggered

 

[Oldmanmopar]

I use Fragola fittings. I never had tis problem. Never had luck with aeroquip or russel. Most all nascar use is fragola.