I too have had problems with float valves and probably have tried them all. My A is a late 31 which has an indented firewall. This Ford better idea places the gas shut off valve on the engine side of the firewall which requires opening the hood to turn off the gas line. A real pain especially when you leave the car in the garage or park on a friends asphalt driveway and forget to turn off the fuel and the float valve leaks.
I have been thinking about this leaking valve problem which may not always be the fault of the valve. I know as many others that the leaky valve problem sometimes goes away for a while after removing the lower bowl and actuating the float a few times. I have also cleared the problem by simply starting the engine and shutting it off or wrapping on the side of the bowl.
My guess is that the float can occasionally bind where it pivots on the the small pin support. If the pin fit inside the support tube is snug or the distance across the float support tube is too close to the uprights that hold the pin, the float could possibly not completely engage with the tip of the float valve. This would cause a perfectly good valve to leak.
My plan is to carefully review the float support and the pin fit on my carburetor, improve the fit where necessary, and monitor the leaking problem.
there is so many variables involved in stopping the drip/leak.
i spent 4 days on one carb before i found why it dripped.
sometimes the float valve and float level valve can be working properly and the carb will still leak. the main and cap jets can leak letting gas run out of the throat of the carb.
i had jets that leaked around what appeared to be a seam.
the float can look good and not leak/sink, it will go up and down properly. but will still not work properly.
i have changed float valves to find the leak does not change. what had happened is, the point at which the needle contacts the top of the float had worn a small impression, i carefully sanded it smooth then polished that area. this lets the needle find its own location to rise properly into the seat.
another thing, if someone has bent that float to try to change the level it may not be pushing the needle up straight.
these are only a few things. i suspect the list is endless.
what I'm saying is some of these fixes are not an afternoon fix. some take a lot of testing and trial and error, be prepared to fail numerous times.
in a previous post i posted a pic of my test stand which helps so much in finding problems.
tom endy has a few good articles on carbs. you should read through.
the key is patients. lots of observation. lots of testing and don't assume things are correct, check.
one more thing i'll say, which many may say is not true.
THAT CARB SHOULD NOT LEAK once it has been repaired.
