AN fitting leaking

[Louie L.]

Guys,
I have completed installing a new fuel system in my car consisting of a sumped tank ,-10fuel line up to the stock rail.

At the rail I had a -10 male steel fitting tigged at the stock location. The issue im havig is that im having a slow drip out of this area. It appears that the male and female are not sealing.

Both fittings are i great shape , there is no stripping or damage.

Any advise??.

 

[Chuck Leeper]

LEAKZ??

Louie, are you sure the weld on fitting is an AN fitting???They are 37* and the more common automotive stuff is 45*. Could also be that the flare face was warped during welding and they are not making 100% contact. Inspect the welded fitting , looking closely for indications of less than 100% contact.
Not a pin hole in the weld, w/ the gas leaking at the bottom of the weld and dripping off of the hose end??
If all else fails, use a pair of GOOD wrenches and apply a "significant" torque to the fitting, while holding the rail weld on.
DO not use thread sealant tape. That can make a leak worse.

 

[Datsunboy]

I do belive that the AN lines can use a special AN gasket as well. Id go ahead and go that route if the drip persists! jegs/summit sells em.

Evan

BTW... i did an on my datsun, and hate the stuff! Man it just hates sealing.

 

[Louie L.]

Thats for the replys.
Chuck,
The thought came to mind about the 37 and 45* fittings. I bought a -12 which was tigged to the sump which was the same brand from the same place, that one doesnt leak but its not under pressure either. But i would think that it would leak too at some point.The leak is not coming from the weld that im sure of.

About the AN gasket ,there are washers and o rings but those all have their own applications.

Still leaking

 

[PRSRIZD_V6]

I wonder if you could get it to seal by fitting an O-ring in the female fitting and screwing it together. It'd be a bit of a cobble-job, but it might get you some miles.

 

[azgn]

Louie, doesn't that set up effectively neck your fuel rail supply line back down to stock size? Wouldn't this be a bit of a restriction?
Ya know, Mr Leeper makes (or knows where to get) a very nice fuel rail with the proper AN fitting?

 

[PRSRIZD_V6]

If 6AN is used with 3/8" lines then how is a 10AN a restriction?

 

[Louie L.]

Woody,
There is no restriction with this set up. I drilled the rail where the stock o ring fitting sealed against. Now i have a straight shot into the stock rail. No necking down or nothing.

Anyways the thing is still leaking. No kind of thightening will stop it.Im affraid to thighten anymore. Its a slow drip, maybe every 10 sec there is a drop.


This sux.... The car is finally running after being down for over 7 months.

Like Chuck says........

Back under my leak!

 

[azgn]

I get the picture Louie.....maybe chat with Chuck about his fuel rail....I've seen 'em on two cars locally with big ass Aeromotive pumps and a trick pick up (no sump)...think those were 12 & 10 AN lines...

 

[PRSRIZD_V6]

Even if it does neck down right at the fuel rail there is still a large advantage to be had with larger lines. The bulk of the restriction is bends in the small dia stock line.

That's why you can get away with running a larger or dual fuel pumps all the time with only replacing the return line. The regulator isn't the restriction, the lines are. Same theory applies to the feed line.

I still agree though, if you're gonna bother you may as well do the whole shot. Go Hard or GO Home.

 

[laz]

I don`t think this will help but steel fitting should not be used with aluminum A.N. hose ends . I haved tryed but it always screws up the hose ends . I always use #8 to feed the rail i can`t see a need for #10 Joe Lubrant runs #8 to the rail with 160 lb injectors. If all else fails try a copper air conditioner gasket take a a.n. fitting with you to get the right size it`s like 3/4 barb.

 

[WFO]

i'm ASSuming a couple of things.

1:the fitting welded onto the fuel rail is steel(kinda hard to weld it if it's not).i'd give about a 99% guarantee that it's 37.5* an/jic.most 45* stuff(sae) is brass.

2:your -10 hose fitting is aluminum.

first thing i would do is look down into the female end of the hose fitting and look at the seating surface.it should have a nice uniform mark where it contacted the male seat of the weld-on fitting.if the mark is wavy or has obvious gaps the hose fitting is probably bad.i have seen this before .i have even seen one where the seat wasn't machined at all,no taper just a flat block of aluminum.thank god i looked at it before i sent it out the door with the customer .


fyi,there are soft copper "gaskets" for tapered fittings,but all the ones i have ever seen are for 45* sae and are designed for low pressure.


later,sean

 

[Louie L.]

-10 overkill....yes ! But it wont be when my off center stage motor goes in.

Im gonna pull the rail and take to the place where i got the fitting and have them double check it. If its the wrong one It was suggested that i have them put their matching hose end on my hose.