Hey all, I'm about to do the brakes on our 2010 A4 2.0T. Pads are due and the rotors appear to be in pretty good shape still. Whats is the minimum acceptable rotor thickness to turn them on the brake lathe? I was going to order new rotors with the pads, but i would like to keep the cost down if I can and just turn the rotors, but I cant find any concrete measurements.

Thanks, in advance,
Nick

 

If they are not scored or warped all I would do is hit them with some emery cloth to take off the glaze. The min thickness is listed on the hat of the rotor. Just pull the wheel and see what it is. How many miles do you have on these rotors . I usually never change or machine rotors until they are either warped (out of flat spec) or scored.

 

they've got roughly 35k miles on them. I didnt even think to look at the hat. Ill have to check that out. There is no excessive runout on them or anything, but there is a little bit of "threading" on the surface of the rotor from the shitty OE pads. Gonna go ceramic and want a nice even finish on the rotor.

 

When you break in the pads they will conform to the rotor. Usually when they get cut the operator takes off more then is necessary. Unless you have some deep grooves I would not turn them. First check the thickness and then the finish. If they get turned to the min thickness they will warp in around 10-15K miles.