Brasscraft is a good choice of brand.
no
Look on the cap that you take off to fill the oil on the valve cover.The brand will be your choice.
Unscrew the old one and replace it with a new one. You'll have to reprime the line and the pump again to fill the void of air that is now in the pipe from changing the foot valve.
There are a number of reasons why pipes might hum when they are turned on. A washer could be worn out and not working correctly. The fill valve on one of the toilets may not be working properly, or it could be your water pressure.
Any valve used to fill a vessel or tank or replenish a trap seal
Replace the fill valve (ballcock). The type that uses a diaphragm, like fluidmaster, will shut it off quicker. Reason that occures: vibrations in the pipe from the fill valve when the water flows through the ballcock ( like a whistle does with air), but water makes a deeper sound and sometimes vibrates quite loudly once that starts. If that doesn't fix it, try replacing the supply water valve.
its a squirrel
replace the fill valve
My experience is when you flush the toilet, the fill valve opens and starts re filling the tank......sometimes if the water pressure is too high, it will "whistle". Close your fill valve until it stops whistling.....usually this slight adjustment will stop it from making that annoying noise
What exactly is overflowing? this can range from a blocked toilet to a faulty washer
To allow toilets to fill from the water line without overflowing.
If you are referring to the water closet fill valve, then you probably have a bad seal. most Ball Cocks fill from the bottom and have a feed line to the bowl. If the seal in the top of the valve near the ball arm is bad you will get water out of the top of that valve. If the line (usually a small hose that goes in to the top of the flush valve) is off it, will also spray water. sounds like the fill valve is bad and should be replaced. A fluid master 400 will fit most toilets and is easy to install. The amount of water in the bowl after flushing is very important to a good flushing water closet. if this hose does not stay in place the toilet will flush slow and clog up more.