Rotor Cracked c

[Hs_m35]

I have a 2006 M35 with about 74,000k on it. A few days back my rear driver side rotor has cracked. Now Im not sure what the problem seems to be. But before this happened everytime I let go from the brake pedal while shifting from Park to Drive or simply waiting at a stop light or stop sign my car never seemed to move until i pressed the Acceleration. I could feel the car kind of driving heavy feeling the pressure of my brake pad. After I reached my destination I could smell a bad odor of brake pads. I now have a large thumping and squeaking sound coming from the vehicle everytime i drive and have left it at home for now. So before I take it to a mechanic or the dealership I wanted to run it by you guys.

Anyone have an idea of what the issue can be?
I have the BrakeMotive drilled and slotted rotors and brake pads from ebay....

Thanks in advance guys any input would be appreciated.

[EniGmA1987]

Could be a stuck caliper that was holding the brake pad down. Constant force from the brake pad while driving would produce a ton of heat and that could cause the rotor to crack. You can get a new set of brakes from a guy named "Brakemotive" on EBay for $175 for all 4 rotors and 8 new brake pads. Then you should also look at replacing the caliper too. I am not sure what stock ones go for, but probably around $250 maybe for 1?

[svard75]

I'm not going to say I told you so, but in reality drilled and slotted rotors are not designed to last very long. Plus it depends on how the holes were drilled. If they were drilled with a standard drill press at normal temps then they will crack. The drilled rotors on mercedes and higher end bmws are cold drilled to ensure there isn't micro fractures that occur due to heat.

Plus how were you expecting to refinish them once the pads wore out?

[rxmclaren7]

i agree with EniGmA1987...this may be a stuck caliper...not good but not hard to replace on your own if you are so inclined! i would not drive the car to the mechanics have it towed, if you have AAA that is, i once had a stuck caliper on my previous car(87 mazda RX7) and it destroyed the brake rotor...i would also look into getting another brakemotive kit as it is cheap enough!! also how many miles do you have on the brakemotive kit??

[szh]

Plus how were you expecting to refinish them once the pads wore out?

Resurfacing drilled or slotted rotors is possible, but expensive - the lathe must be run at much slower speeds to prevent problems with cracking, etc. Not all shops will want to do it!

In general, with high-quality dense iron rotors, you should be able to go through about two to three sets of pads (perhaps four sets, but unlikely) wearing down before the rotors wear to the point where they need replacement. Assuming no resurfacing (which removes material).

BTW, I like the Centric rotors available at Tire Rack for my model year.

Z

[vasekvi]

I'll never get drilled rotors again. The drilled and slotted rotors I had on my last car had many small cracks. I had a set of replacement powerslot cryogenically treated slotted rotors set aside for it but I sold them with the car before I installed them. But even if the rotors didn't crack they still made a humming sound during medium effort braking. I like the powerslots because they have directional vanes to improve cooling,

[szh]

But even if the rotors didn't crack they still made a humming sound during medium effort braking.

Yeah, the sound of slotted or drilled rotors are quite different from plain old iron rotors - some effect of the pads sliding over the removed material spots, I guess. Pitch changes as the speed changes too.

Z