I'm trying to replace stock rotors and pads with EBC red stuff pads and rotors. Everything has gone well but now that im trying to put the caliper on to the new rotor it wont fit. Even without ANY brake pads in the caliper the bracket will not fit over the new rotor. I already verified that i got the right parts and that the right parts are in the right location (rear left rotor is on the rear left with rear brake pads). When I tried to put the new pads in with the old rotor, it BARELY fits over the old worn down rotor. I havent heard any one have any problems with putting the caliper back on when trying to replace rotors. What gives? Thanks in advance!

 

you have to press in the caliper pistons (aka the inside of the caliper) to get the pads to fit. also in the rears you need to do the same but instead of pressing into the caliper you have to turn the + shaped thing on the inside. You won't be able to press the pistons in by hand you'll need some mechanical help, such as a heavy duty clap.

 

my problem isnt with the piston, it is in all the way. My problem is that the bracket that holds the brake pads is not physically wide enough to clear the rotor even without any pads in. so basically, the bracket (the caliper, the piston, and the brake pads are not even involved here) will not fit over the rotor.

 

Check the height & width of new rotor vs. the old. Is the a big difference? Is it possible that the new rotor is part of a BBK wich would require an adaptor for the caliper.

 

how does the new rotor look (thickness wise) compared to the rotor you took off the car? There should be no real visible difference in thickness. Rotors don't wear that quickly to be this noticable a difference. pics would help.

 

^ i agree, seems like a completely different spec rotor

or you have front rotors that you're trying to put on the rear.

 

the new rotor is noticeable bigger, prolly at least 1/4". I verified that the part numbers are right for the parts that i need. I got my brakes off autopartswarehouse.com. Could i have possibly gotten the wrong rotors even though their site says that my parts should be for a 2005 RX8? I'm going out of town this weekend so ill post more findings out on monday. Thanks for previous and future input.

 

Is your RX-8 a Base model (16" rims)?

 

Without the pads in, the caliper is almost 2 inches wide. That would have to be one really fat rotor.

 

These photos are of a front rotor from a RX-8 with the Sports suspension. If your 8 has the 18" rims (sports) the correct EBC rotors would have simillar measurements.

 

I have the 18"wheels, and ive only tried to change the rear driver set up in which case the rotor size should be the same on all models at like 11'9". I've triple checked already that im not putting the front rotors on the rear. I'm not sure what the deal is, the rotor is just too wide for the caliper.

 

Expo1 is right. If you have the base 16" wheels and your trying to put on sport suspension rotors they will not fit. This just happen to me. The rotors where to tall and to fat lol

Sport
322x24mm (12.6" x 0.9")

Non-Sport
Size: 303x24mm (11.9" x 0.9")

Sport or not the backs are all the same the fronts are not all the same.
Back
Size: 302x18mm (11.8" x 0.7")

Check that the Co. you got them from sent you the right size. They just might have sent you the wrong rotors thats all.

Also see Racingbrake.com for rotor size.
-Gil

 

I just measured my new rotors and they are 12.6" x 0.9" in the front and 11.9" x 0.9" in the back. I'm not sure what size my stock rotors on because I havent had a chance to take the wheel back off yet. I already checked the part number with the one online and it matched up with what i should need. The only way I got the wrong part was if the part number is mislabeled on their system (the part number is etched into the hub of the rotor). Even though my car has ever option except nav the only thing i can think of is that the rotors in the back are only 7 inches wide and not 9 like i need. I havent even tried to change any of the rotors or pads besides driver's rear rotor and pads FYI.

 

As requested, OEM rear rotor photos from a GT RX-8