My rear brake pads are worn out and I bought some replacement pads. Local mechanic says it is recommended I relace the rotors everytime I replace the pads. My car as 48K miles, and rotors hasn't been relaced before.

Is it really necessary for them to replace the rotors? Should I have them check if the thickness is under spec? Any recommendation on this situation?

I did buy brand new rear rotors just incase... I can either use it now, or save 'em for later.. What should I do?

Thank you.

 

If it was my decision, I would look at the condition of the rear rotor. If there is a pronounced lip at the outside edge of the rotor, perhaps you will need to replace the rear rotors. If the rotor catches like it is uneven (or warped), then you will have to replace it.

Otherwise I would leave it.

 

If you already have them, and you don't wish to return them, then just put them on and not worry about them for another 48k miles.

 

as a seat of the pants issue I can tell you that I have run two sets of pads to a set of rotors consistently since I bought my 02 off the lot, and have also recommended this for folks I do brake work for. This assumes the rotor shows no 'unusual wear' (there WILL be a lip at the outside but replacement pads of the same type will wear in the same place.....if changing brand of pads I'd change rotors) and this was always for folks who like me don't track the car. I clean 'em up a bit with some very fine grit paper but in no way do I get them smooth. I just take it easy on the brakes for a few days and they have always worked their way in just fine. Depending on what you buy you can also use the aggressive quick bedding methods if that's your style.

if you want to get 'official', look at your new rotors as an example, you'll find a minimum thickness is stamped or molded into the rim someplace and you'll find the same on the original rotors. Get a caliber and measure your wear - if talking a GEN1 rear the minimum is 8.4mm on oem rotors. MINI does NOT recommend turning their rotors.

but like another post....if I'd already bought 'em I'd either return 'em or put 'em on. Why have 'em sit around? If returning means eat shipping .... I'd also put 'em on cuz as you know they are heavy and shipping can be $.