Our home is in the top of a hill. At the bottom corner of our property, it's just low enough to gravity-feed water from the towns highest water reservoir to a tank on our place. It's a large tank, 105,000 litres (about 25,000 gallons).
Was working around the bottom tank recently, and it was wet. Far wetter around there than it should have been. After investigation, it turned out the float on the valve had rusted out and disintegrated to a little pile of rust in the bottom of the tank. *sigh*. Another running repair needed.
I removed the whole valve (or what was left of it) - which took some doing - and managed not to drop it into the tank.
Looks like this wasn't the first repair either! Some butcher had replaced the pivot pin with a roofing nail!
The insides were a little crusty with mineral deposits over the years, but basically sound.
The shuttle is solid brass.
The rubber face on the shuttle has seen better days. Fortunately, with some persuasion, the end cap unscrews and I was able to flip the rubber over and use the (pristine) other side.
The body has been machined out of a single, solid block of brass (except for the exit tube). It's very solid!
I thought the actuator arm was steel, and was going to turn it down and cut a thread, so it would take a float. When I cleaned it, I found it too was solid brass.
So instead, I drilled and tapped it and put some brass all-thread in to extend and mount the float.
Cleaned up the lot. I didn't have any 5/16" brass rod, so I will need to make a pin and replace the (temporary) bolt.
Re-assembled the thing, and returned to service. Working perfectly now, should be good for years to come. So solid, the only thing that might need attention in a few years will be to replace the rubber, and perhaps just touch up the face it mates against.