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Why would this fuel connection suddenly start leaking?
This outlet fuel connection installed by the previous owner started leaking - the U-bend gets wet and it actively drips while running. It was fine until one day it wasn't. I've tried tightening it, still leaks.
Since the hose looks like it comes from the metal line on the frame (that is fixed) your problem could be a weak or broken motor mount. If the motor mounts look ok, then it could be that the hose was a cheap import that is junk. If there is no brand name on the hose, that may tell you something.
While the engine is running, with a dry finger touch the bottom of each arrowed point and examine for wetness. This should help isolate which section is leaking. If none are wet, you may have the pinhole mentioned above. I don't know if these type fittings use o-rings for sealing but that could be an easy replacement -- though you need to ensure the rubber material is rated for gasoline. (Perhaps the previous owner replaced one with non-gas compatible rubber.)
The Teflon tape on the fuel pump fitting is not advised as this should be a mating flared connection where the tape does nothing but seem to help just because it kinda-sorta looks like a pipe fitting.
PS - are those two diagonal lines for the trans cooler? The U-bend certainly looks like it's rubbing on something and you definitely don't want to rub a hole in a cooler line. Make sure they are not making contact, so bend and affix these parts so there's space between.
While the engine is running, with a dry finger touch the bottom of each arrowed point and examine for wetness. This should help isolate which section is leaking. If none are wet, you may have the pinhole mentioned above. I don't know if these type fittings use o-rings for sealing but that could be an easy replacement -- though you need to ensure the rubber material is rated for gasoline. (Perhaps the previous owner replaced one with non-gas compatible rubber.)
The Teflon tape on the fuel pump fitting is not advised as this should be a mating flared connection where the tape does nothing but seem to help just because it kinda-sorta looks like a pipe fitting.
PS - are those two diagonal lines for the trans cooler? The U-bend certainly looks like it's rubbing on something and you definitely don't want to rub a hole in a cooler line. Make sure they are not making contact, so bend and affix these parts so there's space between.
Okay but I'm not interested in having a Jay Leno experience.
I'll probably just look to replace the whole thing up to the carb.
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what year is it? look at getting the stock metal fuel line if it has a stock fuel pump. I know that some of the fuel pumps that are offered dont have that fitting in the correct place so you may have to pay attention to that. I ended up with a lot of poorly made Carter pumps then went to Edelbrock but had to fabricate a solid line for it
Why not go back to the stock configuration? GM designed it to work without leaks. Jerry
Cuz it looks slick 'n race-y 'n stuff!
It came like this with the braided hose and AN fittings on both ends - the other end goes to a filter with AN fittings going to a braided line fuel supply to a Holly Brawler double-pumper.
Ultimately this is a "for now" fix, until I get the motivation to go through the PITA required to replace the pump with a RobbMC unit which is configured differently.
Last edited by brassplyer; Apr 23, 2023 at 01:42 PM.
It’s possible the braided line itself if compromised. That is legacy CPE rubber hose. Most of that doesn’t do well with E10 and E15 fuels. If you can’t find anything else obvious I would look there.
Well...it has teflon tape on a male inverted flare AN fitting so that is not a good sign.......never use teflon tape to seal an inverted flare fitting....it doesn't seal at the threads.....it seals at the flare inside....adding teflon tape will almost always make it worse.
Well...it has teflon tape on a male inverted flare AN fitting so that is not a good sign.......never use teflon tape to seal an inverted flare fitting....it doesn't seal at the threads.....it seals at the flare inside....adding teflon tape will almost always make it worse.
Jebby
I think you have a pipe fitting going into the flare fitting at the pump. That would certainly do it.
Well...it has teflon tape on a male inverted flare AN fitting so that is not a good sign.......never use teflon tape to seal an inverted flare fitting....it doesn't seal at the threads.....it seals at the flare inside....adding teflon tape will almost always make it worse.
Jebby
From what I can tell the leak isn't from where that tape is - seems to be from either the fitting end or the pump end of that 180 deg tube.
I see the instructions on the RobbMC pump say to use Teflon tape on the NPT thread fittings.
Looks like a pin hole in the picture on the "U" bend.
Originally Posted by 67:72
PS - are those two diagonal lines for the trans cooler? The U-bend certainly looks like it's rubbing on something and you definitely don't want to rub a hole in a cooler line. Make sure they are not making contact, so bend and affix these parts so there's space between.
When I got the line off it *had* been rubbing against the trans line and the steel hose dug a pretty good way into the aluminum fuel fitting line - while I can't see it I'm guessing there's a pin hole or crack there which would explain why it suddenly started leaking.
Got a new fitting along with hardware to eventually hook the line up to the new RobbMC pump. I'll of course take care to position the new one so it's not rubbing the trans line.
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Why would this fuel connection suddenly start leaking?
I think you have a pipe fitting going into the flare fitting at the pump. That would certainly do it.