mikeringland Posted February 12, 2021 Share Posted February 12, 2021 Hey guys, I got my big block swap done, but with one hiccup, a fuel leak. The fuel line that goes from my mechanical fuel pump to my quadrajet, drips where it screws into the larger threaded fitting before the small fuel filter. When I start the car, there is a drip enough that it creates a small pool on the top of the intake after 5 minutes. I cleaned and checked all the fittings, everything seems good, nothing seems stripped. What could be the issue??? Mike Quote Link to comment Share on other sites More sharing options...
jft69z Posted February 12, 2021 Share Posted February 12, 2021 You sure it's not coming from the fitting that screws into the carb & just looks like the fuel line itself? There's usually a real thin gasket that goes to that fitting, if it's missing or damaged it could cause a slow leak and maybe weep along to look like the flare fitting. That, or the flare on the tubing itself is bad, damaged, split, etc so it's not sealing. Just a couple of thoughts... 1 Quote Link to comment Share on other sites More sharing options...
MC1of80 Posted February 12, 2021 Share Posted February 12, 2021 Did you use Teflon tape or the liquid version on both the filter cap and the fuel line? Quote Link to comment Share on other sites More sharing options...
mikeringland Posted February 12, 2021 Author Share Posted February 12, 2021 I have not. I always heard teflon tape and gasoline don't mix? Quote Link to comment Share on other sites More sharing options...
MC1of80 Posted February 12, 2021 Share Posted February 12, 2021 Really?¿? That's interesting. 🤔 All these years..... Quote Link to comment Share on other sites More sharing options...
jft69z Posted February 12, 2021 Share Posted February 12, 2021 22 minutes ago, mikeringland said: I have not. I always heard teflon tape and gasoline don't mix? Teflon is inert to gasoline, won't affect it at all. I've always steered clear of the tape on fuel fittings based on the suggestion that it could peel off, etc and cause blockage down the line though. Proper installation is key though when using tape, keep it at least a couple of threads from the end of the fitting when wrapping the threads. Plus it's a pain to remove from the internal threads when removing the fittings, and again, possibly end up down the line. The liquid teflon works good & we used it a lot when I was in the chemical industry with good results (and I still use it). The flare fitting should require NO teflon of any type though, since the seal is at the flare interface, not the threads. If you still have a leak, you need to determine which fitting is leaking and determine what is either missing or damaged. Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted February 12, 2021 Share Posted February 12, 2021 Mine did that when I changed over to the q-jet it wasn't the fitting at all there was some kind of plug (maybe lead) under the fitting. That's where it was leaking I had to get a different carb and that fixed it. Luckily the warranty covered it. Is it a new or rebuilt carb? Mine was a rebuilt unit. Another possibility Quote Link to comment Share on other sites More sharing options...
mikeringland Posted February 12, 2021 Author Share Posted February 12, 2021 It's the same carb I had on my 350. I didn't change anything on it either. Quote Link to comment Share on other sites More sharing options...
Gush's monte Posted February 13, 2021 Share Posted February 13, 2021 Mike, there should be a gasket (either brass or nylon) between the large fuel filter fitting and the carburetor body. That was leaking on my Chevelle’s recently. I went with a nylon gasket as it sealed better than the brass. Be careful tightening it down ( should be a 1” wrench as the threads of the carburetor are prone to stripping). Quote Link to comment Share on other sites More sharing options...
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