I was just wondering if the calipers, rusting should be covered under warranty, i have this problem on both of my 07 Bimmers, the 550 and X5. It just doesn't seem right, I keep the cars spotless but the dam calipers are rusty. What's with that anyway??????

You taking them to drive-thru car washes? If so, that's why. If not, change the soap your using to wash the car.

Do you have a Picture of what you see? I believe the calipers on the 550 are aluminum. The 550?s rotors are steel disks with aluminum hubs.

Sorry I don't know about the X5.

The rotors are not steel, but cast iron. Steel brakes don't work very well.

They all rust a bit.

Ugly, but such is life.

You are joking, right? :lol:

Water oxidizes the cast iron (maybe some alloy now). Cast iron is used because it UNIFORMLY handles and sheds heat the fastest of any metal (remember that cast-iron skillet?). Other metals warp; warp=wobble. The only downside to cast iron is its unsprung weight (and I suppose, that superficial rust). You can wait for ceramic discs, someday, maybe, but hold onto your hat and wallet; they are hugely expensive and don't work well under simple loads (good for racing; lousy around town).

I suggest you drive more and fret less about rust than brake-dusted wheels.
Ray

It is an alloy, as pure iron isn't very useful. It is a type of gray iron. It is used due to it's heat capacity.

You are correct that carbon-ceramic rotors aren't cheap. It's a $23,000 option on the 911. (That's over 19 Logic 7 audio systems! :P )

That alloy mix seems to be changing too. The Brembos on my Moto Guzzi were fat and broad and rusted instantly from splashed water off the ground. On the new K1200 GT (in avatar), the alloy is much more apparent as they are shiny, tiny and drilled by comparison...but superlative in stopping power.

Ray

I'd take the 19 Logic 7's...and hell, they should throw in 1 extra to make it an even 20. :P

I think a lot of people where addressing the rotors and not the calipers. I don't remember mine rusting, but they always looked dirty from the brake dust until I changed pads. I doubt the dealer will do anything about this.

You could paint them with caliper epoxy paint and they would look much better than factory. I would suggest gray or black - black looks really clean.