GTD fuel tank thread

[Simon]

Any idea what size fitting was used (1989 build) as I’ll need a tap (and a new fitting!)

 

[Morten]

Isnt those AN6 or 8 JIC ? With NPT

measure and compare. Link here to charts:

https://anfittingguide.com/wp-content/uploads/2014/01/AN-hose-and-fitting-guide-v21.pdf

Hope this helps
Morten

 

[Simon]

Thanks Morten, I will investigate further.

Simon

 

[Morten]

Find a 1/4in NPT or BSP nipple from a hoseline see what fits

m

 

[Neil]

For sure run an NPT tap into those female threads to clean them thoroughly. Throw away the fitting with the stripped threads and brush off the threads of the other one and clean it with alcohol, etc. It looks reusable. Despite all the cautions not to use Teflon Tape on pipe threads, you can do it safely if you are VERY careful with applying it to the fitting threads. Do not allow excess tape to get into the inside of the hose or fitting- that is what causes problems. Tighten the fitting to the point of being snug; over tightening pipe threads is an invitation to stripping the threads or cracking the fitting.

 

[Ryan L]

very odd, they have marks on the flats, that I would normally associate with left hand threads, but they appear to be conventional.

 

[Frank Catt]

Just weld it on , both parts are ali !

 

[Clayton]

Very odd, they don’t look tapered to me. More of a O-Ring boss style, but the thread OD appears smaller. Could be metric one end and AN flared the other ?
Can you measure the OD of the threads, -6 will be 9/16” , -8 will be 3/4”
The end of concern could be M12 or M14
Or they could be BSPP (Parallel)

Clayton

 

[Brian]

No, that's not npt. No taper. It's a straight fitting (same thread pitch) for a crush washer or O ring. Since I don't see the chambfer, not Oring, It's a crush washer.

 

[Brian]

Once bungs like that are welded, they lose their temper and gall like warm butter.

Oring fittings are not as bad, but consider a NPT fitting into a welded bung permanent. You'll never get the fitting out without the threads coming too.

 

[JP Verweij]

Run a tap through it and use Loctite 542 on install of the new fitting.
Loctite 542 works on straight and tappered connections and is E10 safe.