Fuel leaks from AN fittings

[miketyler 15]

How do you stop these from leaking? I have an anodized regulator and its the pipe end of the fittings that are leaking. I did put Teflon tape on it but it just isn't doing the job. The regulator was an eBay cheapo. Is there something better I can use?

[jmlay 80]

I did not think you needed to use anything on AN fitting threads. Teflon sealer may work better than Teflon tape.

 

http://www.permatex.com/products-2/product-categories/thread-compounds/thread-sealants/permatex-thread-sealant-with-ptfe-detail

[BuckeyeDemon 211]

i have used the teflon paste (looks like pipe dope) on the pipe threads for those AN adapters. i don't know if that is accepted practice or not.

[Brian Conway 264]

Usually paste is for gas's, propane, natural etc. Tape is for fluids usually water. Brian

[shaun071 62]

are there any scratches etc on the mating flares? AN fittings are used in the aircraft industry and from my experiences (I work on helicopters) any scratches etc will cause leaks. Also look for poor fitment of the collars or damage near the collar area on the pipes. Also if the regulator is a cheapo the flare angle may be different to a proper AN fitting

[BuckeyeDemon 211]

are there any scratches etc on the mating flares? AN fittings are used in the aircraft industry and from my experiences (I work on helicopters) any scratches etc will cause leaks. Also look for poor fitment of the collars or damage near the collar area on the pipes. Also if the regulator is a cheapo the flare angle may be different to a proper AN fitting

 

I believe the OP is talking about the NPT fittings. Not the threads on the AN flare side.

 

If the OP is talking about the flare side fitting, then my post is not applicable and I apologize for getting this off topic.

 

NPT to AN Fitting.

[miketyler 15]

Buckeye is correct. This is the pipe side of an aluminum AN fitting and not the flare side. I too worked on aircraft for several years and know they make conical washers for seal problems on the flare side but this is aluminum to aluminum pipe threads I am trying to seal up.

 

I am unsure where to get teflon paste. I have read that Permatex number 3 Aviation gasket sealer will work for this application. This stuff comes in a plastic bottle and is brushable. I plan to pickup some and try this out.

Edited November 10, 2013 by miketyler

[BuckeyeDemon 211]

Buckeye is correct. This is the pipe side of an aluminum AN fitting and not the flare side. I too worked on aircraft for several years and know they make conical washers for seal problems on the flare side but this is aluminum to aluminum pipe threads I am trying to seal up.

 

I am unsure where to get teflon paste. I have read that Permatex number 3 Aviation gasket sealer will work for this application. This stuff comes in a plastic bottle and is brushable. I plan to pickup some and try this out.

 

 

It claimed it can be used for unleaded gasoline. See below datasheet.

 

http://ows.rectorseal.com/product-data/tru-blu/dstrublu.htm

 

 

 

I got it locally at home depot.

 

http://www.homedepot.com/p/Rectorseal-4-oz-Tru-Blu-Pipe-Thread-Sealant-with-PTFE-31630/203490732

 

 

I used it on on the NPT fittings for the filter I installed on my rear frame rail. No leaks, but I have very little time on this car.

[miketyler 15]

I will pick up some of that, thanks!