Sealing a NPT fitting
 

I have a 1/2" fitting that screws into the steering system filter. I tightened it and mounted the filter. It was leaking so I took the filter and put it in a vice and made sure it was VERY tight and used some "Locktite 545". It's still leaking.

Anybody know a good trick to seal a NPT fitting?

Re: Sealing a NPT fitting
 

Try using aircraft or aviation sealant. You can get it at your local auto store.

Re: Sealing a NPT fitting
 

Teflon tape from any auto store, hardware store should do it. To keep it from unraveling as you tighten the fitting, I wrap it clockwise as you're looking at the end of the male fitting.

Re: Sealing a NPT fitting
 

Having worked in the Utility business for many years, when we had a problem NPT fitting, we would wrap the threads with a layer of teflon tape and put a coating of sealant over the teflon tape. Pretty much did the trick every time.
We used Sealtite and Gasoil sealants with great results.

Re: Sealing a NPT fitting
 

First check both threads to make sure that they are all right. If they are any places that do not look good use a tap or die to rethread. Make sure the threads are clean. It maybe a little tough to get it out later but Permatex #1 should take care of the job. Let it cure before putting any pressure on it.

Re: Sealing a NPT fitting
 

I got to thinking after I responded to this thread. I'm assuming that the leakage is just occurring past the threads which is just a little unusual with something like power steering fluid getting past the Locktite. My question is whether there's something else like a flared seat involved? Just curious. If not, Dave has a lot of good advice here.

Re: Sealing a NPT fitting
 

You may have to replace the fitting and run a tap into the hole to clean the threads up. Be careful to only go about 1/4 turn or so after the tap bites or the hole won't let the fitting bottom. Permatex makes a liquid teflon you can get at a good auto parts jobber. http://www.permatex.com/products/pro...&item_no=56521

NPT is a half-assed solution on anything over 500PSI but alot of folks use it because it's cheap.

Re: Sealing a NPT fitting
 

Thanks Guys,

I've used the Locktite 545 before with good results. I don't think I let it sit long enough before reconnecting the hoses. The fitting and the filter a brand new. I think I will give the teflon tape a try.

Dave M.

Re: Sealing a NPT fitting
 

Reinspect it for a slight crack. Its hard to beleave its getting by the locktite.

Gerry

Re: Sealing a NPT fitting
 

I knew it was the hydraulic steering when I read the title. For some reason I've had the same problem on the 4 I've installed. One NPT fitting always seems to leak. Never seems to happen on tranny, oil, or other hydraulic lines!
First off make sure it's NPT and not inverted flare or some other compression dfitting.
Then make sure the female side is not cracked from overtightening.
In the installation manual, they usually reccomend a "paste" sealant. They suggest not using tape because pieces of it could clog/jam in the hydraulics. That being said, it's the pastes that fail. Use some tape, just be sure you start wrapping a thread or two back from the end to avoid and pieces breaking off in the line if you disassemble it.
Gary