Fuel Tank Dilemma

Mon Jul 12, 2004 4:40 pm

When tightening the sediment bowl into the tank, it leaves the lever where it will center on a high point of the underside of the tank. If I back it off, it leaks. Here it's shown as tight as it will go, but not in a good position. I thought about a short pipe nipple, but I don't think there is enough room under there. Is this a "JB Weld" fix like the coolant drain plug?

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Mon Jul 12, 2004 4:52 pm

If you don't have room to add a close nipple, try filing the end of the shut-off lever to make it shorter.

Mon Jul 12, 2004 6:46 pm

Take the bowl off and use a pipe tap to give the threads in the tank a bit of a cleaning. Use some teflon on the threads so it will turn as easily as possible. Looks like you only need a quarter turn or so.

Tue Jul 13, 2004 12:21 am

I haven't been able to locate a pipe tap. Lowe's or Home Depot are limited in that area. I may have to file, or take the pipe nipple and run it in a little deeper. I just don't want to crack anything. After it's cured, does JB Weld do alright with fuel on it?
Thanks,
HR

Tue Jul 13, 2004 4:55 am

HR

Please wait for someone to confirm this, but I thought the tap size is 1/2 inch pipe thread. I think I got one at my local True Value. Paul K. in N.H.

Tue Jul 13, 2004 6:01 am

Threads are 3/8 NPT if you choose to run a tap into the tank.

Tue Jul 13, 2004 9:08 am

HR, the sediment bowls are usually made out of brass or pot metal depending on the age, and are fairly soft. Yours may have been reinstalled a few times and over tightened to the point the threads are a little small. You may find that a $15 sediment bowl assembly and a little thread dope or tape will solve your problems.

Tue Jul 13, 2004 3:54 pm

i believe there is a special teflon tape for fuel contact duty. blue if i remember Dad correctly.
i don't have any, but it's on my 'hope i remember next time i'm inthe parts store' list

Tue Jul 13, 2004 4:06 pm

Hello All
well it sounds like I was wrong on the npt tap size, but I know Home depot has thread tape just for gasoline and k1 at there store . I believe it is in a yellow plastic roll, says right on it for use with gasoline and so on. Cost less than a buck. Paul K. in N.H. :oops:

Tue Jul 13, 2004 6:01 pm

You'll need a small NPT TAP( tapered pipe threads ) It may be as small as 1/8" NPT. Take the sediment bowl with you when you go shopping. While you're at it, get a button die to chase the threads on the sediment bowl too- same size. Just clean the threads only on the male threads; don't take more material off. Then thread the fitting on dry and see where you wind up as far as position. Note where the lever IS and where it SHOULD be. Take the sediment bowl off; then run the tap in till it is going to start to cut; line up one of the tap handles with the "IS" reference mark and then tap deeper till you get to the "SHOULD" reference mark. Put the bowl on and see if it lines up where you want it. REMEMBER! You can always take just a bit more out.....there's no such thing as putting just a bit more back on! Once it goes where it should re-install with the proper pipe joint compound.

It looks like there is teflon tape or pipe joint compound at your flared fitting on the side for the fuel line. This is not correct. The threads on this type of fitting do not form the seal.
The seal is formed between the nipple and the flared fuel line. If this joint leaks you probably need to cut off the old flare and make a new one. It's a flare like they make for brake lines. Consider forming up a metal line for the entire run to the carb that hugs the block. It won't flop around or get caught on a branch like the rubber lines do. Many times the rigid fuel lines on older equip were cut out to add in line fuel filters and for an easy way to drain fuel out.
Happy Fixin' !

Tue Jul 13, 2004 7:30 pm

Remember, when you are using taps and dies on the threads that pipe taps are tapered, and the further you run the tap in, the larger the threads will be, and the deeper you will have to screw the sediment bownl in to get a seal.

Tue Jul 13, 2004 8:08 pm

Marion(57 Loboy) wrote:
The seal is formed between the nipple and the flared fuel line. If this joint leaks you probably need to cut off the old flare and make a new one. It's a flare like they make for brake lines. Consider forming up a metal line for the entire run to the carb that hugs the block. It won't flop around or get caught on a branch like the rubber lines do. Many times the rigid fuel lines on older equip were cut out to add in line fuel filters and for an easy way to drain fuel out.
Happy Fixin' !


If the fittings are original, they won't be flared. They are compression fittings which require ferrules. I make replacement lines out of steel brake line by cutting the flared ends off and adding ferrules. Both types of fittings use the same type nuts, but the female part they screw into in the sediment bowl and carburetor are not flare type. The flared end will not seal correctly and can be dangerous. :shock:

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Wed Jul 14, 2004 5:54 am

Had the same problem on our 450D small gas tank. The only solution is buy a new sedement bowl as the threads are worn and use liquid Teflon. Works 100 %

Wed Jul 14, 2004 5:13 pm

Thanks for all the pointers. I'm just trying to re-furb this '50 model, and as you all know, some of the things you find from previous owners leaves one scratching his head. I do prefer to go back with correct method, and as usual, you guys come through. Thanks.
HR