[Fullback66]

I have a leak (drip) coming from the threads for my rear carb fuel line to the rear carb.
Is there a sealent I can use to fix this?

Thanks,
FB66

[Chief of the 60's]

Never use any sealant on fuel components

[Fullback66]

How do I fix the drip? I tighten it as tight as I can get it. It still leaks. Should I order a new block? the brass could be worn out.
Not even a little Permatex?

Should I order a new block? the brass could be worn out.
FB66

[tom s]

There is a post on this site.You can buy copper flair gaskets used in thr AC biz.They work great on tripower fuel lines.I use them on all my builds from day one.Tom

[cdrookie]

I got some sealant at the local home improvement store that can be used with gasoline. I brushed some on every fitting from the tank to the carb, seems good so far.

[Dick Boneske]

If fuel is leaking from the flare nut that screws into the brass fitting, there are two possible solutions. The reason it leaks is because the flare on the tubing has been squeezed flat due to overtightening or many assembly/disassembly cycles.

One fix was mentioned above--using copper flare gaskets. They look like Chinese hats and are available on line--look for flare fitting gaskets.

The other fix is to replace the fuel line. If you want one, PM me. I have this line, freshly flared.

[bendutro]

Don't use thread sealant unless the fitting seals on the threads. The threads are tapered in that case, like NPT. If not then your flare or gasket is what it at fault and THAT is what needs to be replaced.

[Dick Boneske]

Thread sealant needs to be used on the fittings that screw into the carbs, not on the flare nuts on the fuel lines.

I use Permatex liquid sealant with Teflon on the tapered fittings. It is impervious to gasoline and works well in this application.

[ReelFun]

https://www.grainger.com/product/PAR...e-Gasket-5WRW2

I posted a link above for the copper flares Tom S was refering to. I used them and haven't had any problems.

[Chief of the 60's]

Originally Posted by Dick Boneske

Thread sealant needs to be used on the fittings that screw into the carbs, not on the flare nuts on the fuel lines.

I use Permatex liquid sealant with Teflon on the tapered fittings. It is impervious to gasoline and works well in this application.

You are the only one in the fuel business I know of that recommends any kind of sealant. It is not a matter of a sealant being "impervious to gasoline", it is more of it getting into the fuel system or the carb and plugging up the jets. Teflon tape fragments will do much worse. That is why it is not recommended.

If someone wants to risk it, lean-out their engine and turn a piston into swiss-cheese, knock yourself out. It is not my car.

[AC445]

Post #8 x 2,been using GM liquid teflon since it first came out,no problems !

[carbking]

Sealant on flare fittings can do nothing but harm.

Teflon tape on tapered fittings is a wonderful thing........................FOR THOSE OF US THAT SELL CARBURETOR KITS, BY ALL MEANS, USE IT!!!!!!! (See post 10 above).

Teflon liquid or paste on tapered fittings CAN cause carburetor failure. Teflon is a wonderful lubricant. VERY easy to crack a carburetor housing with the use of Teflon paste or liquid. Since I still have 150,000 + carburetors for sale, USE IT, then I can sell you a carburetor!

Jon.

[AC445]

Hello, Dick and I mean use on pipe threads only. Sorry for the confusion.

[Fullback66]

I think I am going to buy a new line and block. It think it is worn out over the years.
FB66

[Dick Boneske]

You only need a new line or the copper gaskets. The brass fitting is not worn out.

[Dick Boneske]

Originally Posted by Chief of the 60's

You are the only one in the fuel business I know of that recommends any kind of sealant. It is not a matter of a sealant being "impervious to gasoline", it is more of it getting into the fuel system or the carb and plugging up the jets. Teflon tape fragments will do much worse. That is why it is not recommended.

If someone wants to risk it, lean-out their engine and turn a piston into swiss-cheese, knock yourself out. It is not my car.

The suggestion in my earlier post is to use thread sealant on the tapered pipe fittings that screw into the carbs. You are mistaken in stating that sealant is not needed here. Some use Teflon tape, some use liquid thread sealant. The brass fittings into the zinc female threads will not seal against fuel leakage without some type of sealant.

Common sense dictates being careful not to allow any tape or liquid sealant on the ends of the fittings where it will enter the float bowl and cause problems. I prefer the liquid sealant because it's less likely to cause a problem--easy to wipe off the end of a fitting if you inadvertently apply it to the end of a fitting.

Common sense also dictates not tightening the brass fittings excessively, whether using Teflon products or not. The fittings only need to be tight enough to stay in place while you install the fuel lines.

It is common on these 50+ year old carbs to find that the female threads are stretched to the extent that the brass fittings bottom before they're tight. In some cases, you can get a decent seal by using several wraps of Teflon tape, but in most cases, a sleeve needs to be installed by someone with the proper equipment to save the carb from the scrap heap.

There is no need to apply any sealant to the flare nuts or flares on the fuel lines. I apply a small amount of oil to the fuel line flare where the nut contacts it so, when tightening the flare nut, the fuel line does not twist and distort.

I've done hundreds of Tripowers as described above with no problems as a few posters have suggested. Common sense does wonders.

[Kenth]

Originally Posted by Fullback66

How do I fix the drip? I tighten it as tight as I can get it. It still leaks. Should I order a new block? the brass could be worn out.
Not even a little Permatex?

Should I order a new block? the brass could be worn out.
FB66

The flare may not been seated properly.
Try loosen the nut and put a drop of engine oil under the nut before tighten it, tighten and loosening the nut a couple of times and tighten the last time just a little more (no gorilla arms) to seat the flare.
I always get them drip-free this way.

FWIW

[61-63]

I no longer do tripowers, and do not like the darned things, but if the threads in a tripower airhorn are worn to the point where the brass fuel block cannot be tightened so that it will not leak then the threads in it need to be replaced by installing tapered inserts. I do not recall the brand name although I have some and have used them. They and the installation tool are expensive but they work and will save an airhorn. Mike Wasson at pontiactripower.com put me onto this years ago. I've only ever used Teflon liquid on carburetor vacuum plugs never the fuel inlets and never used tape on anything having to do with fuel. As several have said your problem is more than likely the fuel line which has been on and off so many times the cup in it is crushed and will no longer seal. This happens with metal fuel lines on AFBs too.

I came back and edited this post - the tapered inserts are made by Belmetric and the kit is $100.09. That is expensive but a new airhorn costs more than that I think?

https://www.belmetric.com/1827-npt-k...hbd53hdv9nr827

[Dick Boneske]

Yes, there are several brands of thread inserts that allow us to save airhorns with stretched threads. A repro airhorn is about $90. Most kits to do inserts cost about $100, and have parts to do four or five airhorns. I've done many, all with good results.

I'm sure many airhorns were scrapped rather than having the threads repaired.

[#1965GTO]

I have to assume that you are running a dual feed Holly. Check the end of the dual feed line to make sure it not cracked. Of course there is a gasket between the float bowl and adaptor. If there is a leak at either of these places and a new gasket doesn't fix it get new line set if there is a crack. Sealant isn't made to repair cracks in the line or fittings. Hey it's cheaper than and engine fire.