I mentioned a hair dryer not a china fright jet engine.

I also mentioned a soldering gun or iron, not a torch with an open flame,
----- way to much heat on a small thin float.
I like 37/63 rosin flux core electrical solder.
Also an once of Muriatic acid diluted with chips of a zinc jar lid
works wonders on cleaning radiators for repairs (or corroded floats)
Guess I should of mentioned CAREFULLY apply warm air
When testing the float: if it is warmed in warm water, then submerged in cold water, it will suck in water if it has a leak.
And you will hear it sloshing inside when shaken, so back to heating and looking for the leak
Use a small soldering iron or gun next time.
( like the ones for circuit boards)----( or wood burning sets)
I'm not sure you fixed the minuscule leak, you possibly just blew out the
sweated seam.

Time will tell.