That depends on what finish your rims have. A acid based wheel cleaner will lift about everything, but its to strong in most cases for un-polish or some clear coated rims, it will stain them big time.
The real baked in dust I use a steamer and that lifts most everything in its way!!
You need to tell us what your rims are finished in
brake dust thats left on for too long can start to eat (pit) into the metal, i see it alot on mercedes and bmw wheels, i think its a combination of the soft comp. brake pads, and their wheels, for some reason, seem to be a little on the weak side as far as holding up against damage.
Beemerboy,
Ever had any problem with the steam cleaner and the wheel finish? I have the Shark Steamer, and my wheels are painted and clearcoated. Is the steam safe to use on this finish?
Wheel Wash from Top of the Line is a great wheel cleaner. It works almost like an acid but it's much safer and can be used on all types of wheels. It cuts right through brake dust and if it's caked on, just give it a 2nd application.