Tricky little buggers these and I've got a few of them. This time they were not the original problem. It started with the hurricane taking the lid off the tinaco and then the wind then beat the float around until it broke. I bought a new bronze float valve but couldn't get it to seal. Bought a plastic one and my brain went dumb and I couldn't figure how to install it. Called a plumber that a friend knows and wa-la. He only wanted 60 pesos (about 4 dollars) but I gave him 100.
Before it got dark I had more water spilling but this time out of the breather pipes. Called the plumber again and he knew right away it was the check valve. The flapper valve inside closes to the tinaco when there street pressure and when there is no street pressure it opens and the tinaco becomes the water source. Sure enough the flapper was stuck open. Take that plug on the top off and a little grease and a screwdriver loosened it up. He also capped a breather pipe he said shouldn't be open.
While he was there I had him look at another valve for my pump house that has been leaking for over a year. We shut the water off and he just put new teflon tape on the plug threads. It's dry now. He wanted 120 pesos for this trip. Two things at 60 each I guess. Nice guy but no English.