Leaking carb.

E

emmit

Junior Member
Have rebuilt the carb. All new internals. Fuel still leaks slowly out when engine is off. Am going to try a gross jet this time. Anyone else have this issue? Friend of mine said that many gravity feed carbs. Have this issue. No real fix?
Thanks
 
If it leaks right away it certainly points to the float valve. If it doesn't start leaking right away after you turn off the car. say after 5-10 minutes you should inspect the float itself. I know you say it's new but that is not always enough. I chased this problem for months before I swapped out my float. Fixed it instantly. I use the Viton rubber tipped float valve.
 
Yeah, the float i have not changed yet. It does not seem to be filled with fuel when i have had the carb. Apart, but who knows. I will just get a new one and try it. *********anyone else have any ideas?*****
thank you
 
When you park the car, shut the fuel off with the engine running and let the fuel bowl run out of gas.

If you come back after a while and the carb is dripping again, fuel is getting past your shut off valve, filling the carb bowl again and you have a leaky fuel shut off petcock valve.

If it doesn't drip, then you can put your money into fixing the carb.

It may be your float having wear. Read the following link about float wear.
http://www.abarnyard.com/workshop/carb-1.htm
 
The viton tipped needle and seat is the only way to go. I set them up using 5/8" as directed. I use a kit with a clear plastic tube from under carb. to above fuel bowl it will show you the level outside of the carb. Bolt carb to a piece of steel and clamp it to a drill press table, make sure it is level fill the carb. with gas and leave it over night. This is the way I do them and have had success with the ones I restored. I hope this helps. JIM.T.
PS I don't shut my valve off!!
(1931 ford late tudor sedan deluxe.)
 
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submerge the float in near boiling water. If there is a leak it will bubble out due to the increase in pressure in the float.
 
A carb will not leak if it is properly rebuilt unless there is dirt lodging between the needle and seat. Don't ever dismiss a leaking carburetor as normal
 
I found on mine that the width of the new gasket was wider than the casting on the front of the bowl. It was sticking out inside and catching the float from fully raising to shut the valve. Trimmed the gasket and no more overflow leak.
 
I set my carb up on work bench,using a lawn mower gas tank higher than carb first with water carb bottom removed carb setting on glass jar open shut off water flows as in car when level rises check shut off for float level and needle leaks I think all the valves are ok but all needs checked,I use original,now test with gas with caution,if this test ok,like said make sure nothing is in way of float,also jet heights are correct,zeniths should not leak,mine does not
 
After I rebuilt my Zenith with new parts it leaked. I replaced the new needle valve (supplied with the kit) with the old original one and voila`...no more leaking
 
Patrick L. said:
I prefer the Grose valves..
Click to expand...

Have you ever had the small ball in this style valve stick in the seat and not want to come loose? Even tapping the side of the carb with a screwdriver handle would not dislodge it. I had to take the valve out and spray a shot of carb cleaner in there to really get the small ball free again. Very strange.
 
emmit said:
Yeah, the float i have not changed yet. It does not seem to be filled with fuel when i have had the carb. Apart, but who knows. I will just get a new one and try it. *********anyone else have any ideas?*****
thank you
Click to expand...
Make sure when you change the float, you change the pivot pin at the same time. It is brass and wears the same as the float in this area and will cause a sticking float.
 
Lets think, "Where else can it leak?" You got the obvious float suggestions but what about all the new stuff in your rebuild; new jets and gaskets. Some of those jet gaskets have manufacturing burrs the wont let the jets seat property. That seat is to help seal the bottom half from leaking gas. Also the suspect the jets where the tube enters the nut, they can leak there too. Check the threads on the jets, do they stop part way on the nut? This can give a false sense of tight. I've also seen cracks in the casting at the threaded jet bosses too.

Just a few "looksees",

GW
 
Thanks for all the tips. It looks like i will have quite a few more things to check. Aftermarket items are certainly not original items. Alot can be said for " they do'nt make them like they used to." but i should be able to get it eventually.
 
After taking the winter off, i decided to check my timing gear marks. As when i changed the maserated gear the first time it was ruined so i guessed to where to line it up. Well, it was off by 4 teeth. I did not know about the mark on the smaller gear and the two having to be lined up. When i took the maserated gear off i thought i was close when i slid the new one on, but was not. The two marks lining up solved all my above issues. I appreciate all the help that was givin,but i will be sure to look over my (new mechanics manual)! Before venturing to deep again.
Thanks again.
 
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