redidnarb

I accidentally bought the 28mm brakes and rotors package from RockAuto. The brakes didn't fit my car, but the rotors looked the same to me so I used them and bought different brakes from store. I later found specs and see there are some differences and wanted to get your opinion.

Are the 28 mm rotors going to be safe for us or do I need to change them back to 32 mm?

Centric parts website specs:
28mm front https://www.centricparts.com/disc-brake-rotor-121-44125
32 mm FR https://www.centricparts.com/disc-brake-rotor-121-44139
32 mm FL https://www.centricparts.com/disc-brake-rotor-120-44140
The picture for the FR rotor doesn't seem correct to me bc the tiny holes are not diagonal like the old 1 I have and like the left ones.
I messaged Centric and they said: Fri, 06/28/24 6:55 am Hello Brandi, We do offer directional rotors for certain models - The 121.44139 and 121.44140 have cooling vanes designed for them specifically, and don't have to follow the other look of the other rotors, so they are just a different design. They are correct though. Thank you for contacting Centric Thu, 06/27/24 4:38 pm Subject Product InformationMessage: Hello everything I've read says the rotors for cast 60-32 have 32mm rotors with directional cooling vanes and so the LH and RH rotors are different. I noticed the 2 tiny holes are diagonal on the front left but straight on the front right. I'm looking at rotor parts 121.44139 and 121.44140.

Thank you!

Brandi

TopNotchIN

@redidnarb Those small holes you're referring to do not affect your brakes whatsoever. It doesn't matter what position they're in. They are there to aid in the removal of the rotor from the hub. If you are removing your rotor from the car, the rotor can be rusted to the hub making it difficult to remove. Those holes are threaded so you take a bolt and screw it into the hole until it pops the rotor loose from the hub. That is the sole purpose of those holes.

I cannot give a definitive answer to your question about the rotor sizing. The difference I see between the rotors is simply the overall thickness (32mm vs 28mm) A 2009 IS250 with casting 60-32 specifies the correct rotors are 32mm.

redidnarb

So, I bought the 32 mm rotors to put on instead which had different part numbers for left and right side. We've taken them out of the boxes and cannot determine which is left or right side now. Any suggestions?

We got Centric 121.44139 and 121.44140.