My front brake only. Using kool stop salmon cartridge v-brake pad. I've cleaned the rims, sanded the pads, adjusted the brakes all different ways, adjusted the toe in, switched the front and back brakes (non cartridge), I've let them wear in for over a month, and they're still loud.
Once, I got them to almost stop, but they would squeak when I got to low speeds, and sometimes they stop when its raining, sometimes they keep going in the rain, or they always squeal. I don't know what to do besides try ordinary black pads again.