Moparts
six pack fuel leak at carb
Posted By: KARLN
six pack fuel leak at carb - 07/08/11 04:29 AM
I had a fuel leak on my outer six pack carb at the fuel inlet fitting. I changed the fitting and installed a new line. Now I have a fuel leak at the other end that goes into the metal block. When I removed and reinstalled it started leaking at the fuel inlet fitting again.
Any ideas on how to fix this leak?
Posted By: DAYCLONA
Re: six pack fuel leak at carb - 07/08/11 11:21 AM
apply a thin film of liquid teflon to the threads before assemble,....NO TAPE, and use a proper TUBING WRENCH, a reqular wrench will distort/egg the line fittings the tighter you tighen the fitting, just making the leak worse
Posted By: KARLN
Re: six pack fuel leak at carb - 07/08/11 04:42 PM
thanks for the suggestion. I hope this solves this frustrating fuel leak issue.
Posted By: jbc426
Re: six pack fuel leak at carb - 07/08/11 08:43 PM
I often get rid of small fuel and brake line leaks at inverted flare fittings by tightening, loosening, and tightening several times. I assume it kind of seats the mating surfaces together. Don't over-tighten.
Posted By: FJ5_Fish
Re: six pack fuel leak at carb - 07/08/11 09:16 PM
I am thinking the stuff is 1/2 chewed up. Maybe get an OE fuel line kit, all the correct wrenches and start fresh. Years ago (decades) I ground up some wrenches to fit the float bowl fittings and bought flare wrenches as well. Also - use wrenches to hold the brass blocks while tightening up all the lines. Tighten every fitting up a little at a time until you are done and you should be good to go.....I have never had to use sealants.
Posted By: KARLN
Re: six pack fuel leak at carb - 07/08/11 11:34 PM
thanks for all the suggestions.
I've installed these lines many times and never had an issue in the past. This time is different. I had a spare OEM line kit so I've installed a new inlet fitting on the carb and installed a new line. I've been careful to use line wrenches, hold the brass fitting and not overtighten but can't seem to stop the leak.
It seems to stop at the carb end and start at the block end.
I'm going to grind down the wrench to hold the inlet fitting and try installing again
Posted By: superwrench
Re: six pack fuel leak at carb - 07/09/11 03:38 AM
I've tried this: Any time I have to crack any of the lines, I always loosen ALL the connections at the fuel blocks.....then tighten them equally in sequence. Nver had a problem since...and I am in there MANY times a year.
Just a suggestion.
Posted By: hemi68charger
Re: six pack fuel leak at carb - 07/09/11 04:36 PM
With all my years owning six packs, one of the most important aspects on installation is getting all the fittings started first. Then, rotate around and tighten them up. I never mess around with screwed up fittings/lines. I have used fuel resistant teflon tape in the past and it helps. But, again, the biggest thing is getting all the fittings started everywhere then rotating around tightening them..
Posted By: topside
Re: six pack fuel leak at carb - 07/09/11 04:48 PM
We make & sell a 1" wrench specifically for Holleys; the ends are clocked so they clear everything including the firewall, and they're hardened.
Got tired of trying to make normal wrenches, which are too thick, too large, and too long, work for that job.
$22.00 + $3.00 shipping.
Posted By: hemi68charger
Re: six pack fuel leak at carb - 07/09/11 06:33 PM
Quote:
We make & sell a 1" wrench specifically for Holleys; the ends are clocked so they clear everything including the firewall, and they're hardened.
Got tired of trying to make normal wrenches, which are too thick, too large, and too long, work for that job.
$22.00 + $3.00 shipping.
Another thing and this brings to light, always use a 1/2" line-wrench. You'll be happy you did. You could always use a regular 1/2" to start things, but do the final fastening with the line wrench.
Posted By: KARLN
Re: six pack fuel leak at carb - 07/09/11 09:25 PM
thanks guys. I'll try your suggestions and keep you posted.
Posted By: KARLN
Re: six pack fuel leak at carb - 07/10/11 11:35 PM
tried all your suggestions and still have the fuel leak. Now its on the block end where the fuel line treads in. I've loosened off all the fittings, installed and tighten each one equally, holding the block with a wrench.
Only thing I haven't done is put any sealant on the treads.
This issue is holding me up from completing my T/A and getting it on the road.
Any other suggestions would be greatly appreciated.
Posted By: 62maxwgn
Re: six pack fuel leak at carb - 07/11/11 01:06 AM
Yes,if you have stainless lines,get rid of them,other than that you're on you own.
Posted By: KARLN
Re: six pack fuel leak at carb - 07/11/11 01:53 AM
I'm sure the new line kit I installed was SS. I guess I'll have to order a new set.
Posted By: screamindriver
Re: six pack fuel leak at carb - 07/11/11 01:57 AM
Take a good look at the brass block mating surfaces...If they're deformed I'd spring for the whole kit instead of just the steel lines...
Posted By: DAYCLONA
Re: six pack fuel leak at carb - 07/11/11 02:12 AM
Quote:
Yes,if you have stainless lines,get rid of them,other than that you're on you own.
I've plumbed plenty of six pack cars with steel or stainless, as well as braided SS/AN fittings, never had a leak issue with either that couldn't be solved in under 10 minutes,.....again the OP has tried everything BUT liquid teflon on the threads, esp if he has SS lines, the teflon won't "hurt" the carbs....
FYI I run nothing BUT stainless fuel/emmission/brake lines on my personal sixpack cars,....Sorry, but I can't fathom the issues I read about on this board regarding line leaks 
Posted By: JohnRR
Re: six pack fuel leak at carb - 07/11/11 04:48 AM
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Quote:
Yes,if you have stainless lines,get rid of them,other than that you're on you own.
I've plumbed plenty of six pack cars with steel or stainless, as well as braided SS/AN fittings, never had a leak issue with either that couldn't be solved in under 10 minutes,.....again the OP has tried everything BUT liquid teflon on the threads, esp if he has SS lines, the teflon won't "hurt" the carbs....
FYI I run nothing BUT stainless fuel/emmission/brake lines on my personal sixpack cars,....Sorry, but I can't fathom the issues I read about on this board regarding line leaks
Mike , you are a very sharp guy but I can't figure this one out , does putting the thread sealant on the threads help the nut get tighter ? The reason I ask is because on this type of connection the threads are not the seal point , the flare on the line and the block the line is screwed into are the parts that make the seal .
Posted By: DAYCLONA
Re: six pack fuel leak at carb - 07/11/11 10:36 AM
Quote:
does putting the thread sealant on the threads help the nut get tighter ? The reason I ask is because on this type of connection the threads are not the seal point , the flare on the line and the block the line is screwed into are the parts that make the seal .
John in your own often used words,...."Ding Ding Ding, we have a winner!" 
....Ih the plumbing world, thread/pipe dope/sealant, which ever you prefer to call it, has one task, to lubricate the threads, esp dissimilar mat'l, and ESP STAINLESS STEEL, prevents galling the threads, if you don't gall the threads, you can achieve a seal on NPT, or inverted flair, bubble flair/etc/etc or compression fittings by extending the thread travel and allowing the fitting to perform it's mechanical seal, regardless of the type of seal involved,...the OP probally has wrenched the piss out of the lines by now,....probally will need a new set,....this falls under the ol'sayin,..."A little dab, will do ya".....
Posted By: 62maxwgn
Re: six pack fuel leak at carb - 07/11/11 01:35 PM
Quote:
Quote:
Yes,if you have stainless lines,get rid of them,other than that you're on you own.
I've plumbed plenty of six pack cars with steel or stainless, as well as braided SS/AN fittings, never had a leak issue with either that couldn't be solved in under 10 minutes,.....again the OP has tried everything BUT liquid teflon on the threads, esp if he has SS lines, the teflon won't "hurt" the carbs....
FYI I run nothing BUT stainless fuel/emmission/brake lines on my personal sixpack cars,....Sorry, but I can't fathom the issues I read about on this board regarding line leaks
Mike.I've used both over the years (and a lot) and never had a problem with either one,my bird has stainless,has been apart off and on many times in the last 18yrs and no leaks. (and "never" had to use a sealer of any kind) 
The secret if you want to call it that is the correct wrenches and knowing how much to tighten and when to quit.Look at most used fittings,most have the edges rounded from not using line wrenches.I've also had some carbs to restore that had the fitting so tight that the owners cut the fuel line because they couldn't get the nut loose from the inlet fitting.Regular steel lines are a little more forgiving if you don't have the right tools and are unfamiliar with the process.
Posted By: DAYCLONA
Re: six pack fuel leak at carb - 07/11/11 03:11 PM
Quote:
Quote:
Quote:
Yes,if you have stainless lines,get rid of them,other than that you're on you own.
I've plumbed plenty of six pack cars with steel or stainless, as well as braided SS/AN fittings, never had a leak issue with either that couldn't be solved in under 10 minutes,.....again the OP has tried everything BUT liquid teflon on the threads, esp if he has SS lines, the teflon won't "hurt" the carbs....
FYI I run nothing BUT stainless fuel/emmission/brake lines on my personal sixpack cars,....Sorry, but I can't fathom the issues I read about on this board regarding line leaks
Mike.I've used both over the years (and a lot) and never had a problem with either one,my bird has stainless,has been apart off and on many times in the last 18yrs and no leaks. (and "never" had to use a sealer of any kind) The secret if you want to call it that is the correct wrenches and knowing how much to tighten and when to quit.Look at most used fittings,most have the edges rounded from not using line wrenches.I've also had some carbs to restore that had the fitting so tight that the owners cut the fuel line because they couldn't get the nut loose from the inlet fitting.Regular steel lines are a little more forgiving if you don't have the right tools and are unfamiliar with the process.
I agree with you Bill,...I don't have any issues either, I've been "wrenching" for a living and hobby for the last 35+ years, you learn the ends and outs of what/what not to do, In regards to a sealer it's more of a thread lubricant on a compression/flare to prevent thread gall, which if not used IMHO can kill not just the threads, but prevent a good compression on the mechanical seal.. 
Mike
Posted By: KARLN
Re: six pack fuel leak at carb - 07/11/11 03:14 PM
all your suggestions are noted and appreciated.
I'm going to order a new a complete set of lines/blocks as I can't afford to have an engine fire. I've had my lines on/off a hundred times and this is the only time I've experience this kind of leak.