I got out for a drive today, and when I returned, I noticed the back of the carb was wet with gas. In fact, I was seeing a drip off the bottom of the throttle linkage. (Right onto the exhaust manifold of course.)

I rebuilt this carb just a couple months ago, and had finally adjusted the screws on the float bowl cover just right to stop that drip - what a pain that I now have a new one...

Any idea what could cause a leak in the back of the carb like this?

 

Here's maybe a better picture

 

Not that it helps, but mine does that too (although mine also seems to be seeping fuel from the throttle pivot as well).

 

Man, i feel your pain. I went through this a while ago but after a couple carbs i seem to have found the correct combo. It looks to me as though there is a drop of gas on the nut that holds the carb to the manifold. If that is the case the only place i think that could come from is "up" towards the top. There is a overflow(if your float/needle sticks) that wold literally spill it on top of the carburetor and allow it to possibly run back. Can you see lots of gas dripping (dangerous of course) when it's running? Maybe take the air cleaner off to get a better look. I'm sure you've done all this but maybe take the air cleaner off, dry the whole thing really good with rags and air see if you are getting anything leaking around the bowl(probably not) when it's not running. You don't have a glass bowl on it so it's hard to see the fuel level. If it stays dry for a while (hour or 2) then maybe start it and see if you can find out where it's getting wet right off the bat. It could be coming out of the choke or throttle plate shafts but you need to clean it up and find out for sure. I was about ready to pull my hair out on mine, turned out to be a warped bowl cover AND a stuck float causing it to come out on top of the carbureter through the overflow. Once i fixed that i then had to deal with the leaking cover. The first time it happened i noticed what i though was "steam" coming from under my hood and here it was gas dumping onto my exhaust manifold. I just sat there and prayed it would evaporate (fire extinquisher in hand of course). I then mounted a fire extinquisher inside my truck behind the driver side seat just in case.

One more thing that it hopefully is not. These thinks are know to develop cracks in the bowl or body due to over tightening to stop the notorious leaking float bowl cover. Obvsiously exhaust your other ideas before thinking the worst.

 

Thanks BHale. I haven't done too much troubleshooting yet, just wanted to see if it looked familiar to anyone. Thanks for all the detail in terms of things to check. I'll get out there to take a look later today.

- Bill

 

I was having the same problem with mine and found it was leaking from the accelerator pump diaphram, replaced it and worked fine after that. I think the best thing to do is dab a towel and see where it's getting wet then trace it where it's coming out of. Good luck I hope this helps.

 

One thing to be aware of with these carburetors is the float setting. With today's gasoline I find I have to set the float a lot lower than factory spec due to the ethanol. By my memory I think I set my float down about 1/4 inch lower than factory spec. Too much fuel in the float chamber can flood the carburetor and leak out in all sorts of places. There is a decent thread about it here: https://www.ford-trucks.com/forums/1...start-ups.html

 

Thanks '52 Ford. I believe I replaced the accelerator pump diaphragm when I did the carb rebuild just a few months ago. I guess there could still be something wrong there, but it's at least a new part.

Thanks 38.
I'd seen that thread before but didn't initally suspect I had a flooding condition.
I wish my bowl was glass so I could see where my float is set currently. I wouldn't be surprised if it was high for the reasons you stated, but I'm not sure how to tell. Will need to research that... Thank you.

 

I am just curious if anyone has tried Recreational fuel in their trucks yet? we call it rec 90 up here in the mitten, but supposedly it is non-ethanol gas. might solve some issues...? I know for us it runs about 1$ more per gallon. I'm thinking it might be worth it though.