Clack

When I replace the pads? I think yes but figured it was worth an ask.

snagitseven

Not necessarily. If the rotors are worn down to the manf. minimum thickness, grooved or you are experiencing brake pedal vibrations, you probably should change both rotors and pads. Otherwise, you may be able to defer changing the rotors and just do pads. Some say you can get two sets of pads out of a set of rotors. On the other hand, if you also change the rotors, you are starting fresh with a complete, new set of brakes. My brakes are just about there at 50K miles and my new rotors and pads are sitting in my garage, ready to go.

Clack

Thank you. Zimmerman's weren't terribly expensive so I went with them as well.