What is the BEST sealant for threads??

[homelessduck]

I just finished my swap from the stock fsv to manual valves. The threads on the fittings on the valves are leaking.

I used Permatex type 3 aviation sealant. It said it would work on threads but it is dribbling.

What do you guys use? It would have to be something I can get locally.
I prefer a hardening sealant. I have had nothing but bad luck with this type 3 non hardening stuff

 

[lotzagoodstuff]

Loctite 565

 

[idiabuse]

sediment

I just finished my swap from the stock fsv to manual valves. The threads on the fittings on the valves are leaking.

I used Permatex type 3 aviation sealant. It said it would work on threads but it is dribbling.

What do you guys use? It would have to be something I can get locally.
I prefer a hardening sealant. I have had nothing but bad luck with this type 3 non hardening stuff

depending on how bad the leak, usually seepage stops leaking all by itself when the leak gets stuffed up with sediment that is in your tank and you pump in everytime you fill up at the station.

Pipe thread fittings are tapered so the leak is small, that is your using pipe thread?


Javier

 

[homelessduck]

I'm assuming it's pipe thread , it's just a brass barbed fitting threaded into the valve .

Thanks guys!

 

[Dave 001]

Loctite 565

x2. Awesome stuff.

 

[homelessduck]

Actually, it's leaking from one of the 90* fittings, on the hose barb side. It's a compression fitting there. Tightening it might stop it but it is already pretty tight. I'm thinking I should just take them all apart and reseal them with the loctite 565 ..

 

[riotwarrior]

In order to have type 3 Aviation sealer work the threads MUST be clean of all diesel first...otherwise it won't seal correctly.

Again this is a situation where SURGICALLY CLEAN is paramount to sealing things...as always IMHO....vehicles DON"T have a imune system to heal small weaping wounds....everything has to be perfect first time around!

 

[franklin2]

Flare and compession fittings do not seal on the threads, so sealant probably won't help in those areas.

 

[homelessduck]

Here is the fitting I'm talking about. It's leaking where the barb threads into the 90*

You must be registered for see images attach

 

[homelessduck]

Everything was spotless. I was super **** about it because I always have bad luck with gaskets and sealing anything. So should I just tighten it or do I need new fittings? I honestly think I over tightened it, if that's possible.

 

[franklin2]

That hex on the 90 that the barb threads into; Does that spin on the 90? If so, there is probably a cone in the middle of the hex that seals that area correct? If i am guessing right, i would take it apart and see what the barb fitting looks like on it's ID. Most of the time you luck out, and the ID of the pipe fitting(your barb) is machined well enough that is compresses against the cone on the 90, and seals well enough. If the ID of your barb fitting is rough, it may not seal very well on the cone of the 90.

I am guessing on all this from the picture, it's hard to see it without taking it apart.

 

[RLDSL]

I still cant tell what youve got there, if its something oddball, but if they are simply pipe thread both sides aside from teh barbs going to the hose, it looks like that one pipe fitting was overcut with the thread ing tool and youve bottomed out, in which case, nothing short of brazing that sucker in there is going to stop that leak.

 

[homelessduck]

Yes, the nut on the 90 spins. On the inside is a male cone. The barb is not a female flare, it's just a basic pipe thread. Did I get the wrong parts?
How tight does it need to be?

 

[homelessduck]

The 90's are pipe.thread into the valve. Then it has a flare fitting (?) , a cone with a nut, and that seals to the hose barb.






EDIT : Does the barb have to be tapered on the inside to.seal against the cone on the 90*?

 

[franklin2]

The barb doesn't have to be tapered, but it needs to be machined smooth with a good straight consistent edge that can smash into the cone. If it's rough or machined out of shape, then it won't seal. If you have a tool that countersinks holes for flat head screws, you could probably take the barb and put it in a drill press, and then chuck the counter sink in the drill press and run it down and kiss the inside of the barb fitting to clean it up enough to seal.

I would take it apart first though. You should be able to look closely at the brass barb, and see where the cone has been smashed against it, and possibly where it's not smashed very well and thus not sealing.