Brake cleaner for diskbrakes unless it's a sound of metal on metal and you have to replace the brake pads. And for rim brakes if there's a metal sound a stone i

Brake cleaner for diskbrakes unless it's a sound of metal on metal and you have to replace the brake pads. And for rim brakes if there's a metal sound a stone is stuck in the rubber part of the brakes, either get it out or replace as well if it's already worn down a fair bit.