Replacing rotor and upgrading caliper, the old rotor centers the new caliper, but the new rotor is a bit offseted to the hub. The rotor is already fastened so that's how it will run if wheels are bolted. Rotor diameter and surface are the same. In terms of clearance, rotor can rotate freely, and the brake pads fit just fine. I was told by my mechanic friend that once I engage brake, pistons will compensate for the offset.

So is this ok? Thanks for any advice in advance!

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  • Pretty sure the fixed-type calipers need to be centered as best you can - kits usually come with shims to do that. Floating calipers are the ones that don't need to be centered at all, really.

    Call the brake manufacturer and ask

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    In this case I have to shim between the rotor and the hub, that seems unsafe am I right?

    parent root

    You would be shimming the caliper, not the rotor, if that's what they recommend

    parent root

    You'd shim the caliper

    parent root

    I have a brake kit that shims the rotor off the hub face but its only 0.080" the way yours is off looks like you can shim the caliper to make that work.

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  • IF there are pistons on both sides fed by the same hydraulic line OR pistons on one side and it’s connected to the other side with FREELY sliding, clean, lubricated slides THEN yes, it all self adjusts

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  • Id say your mechanic friend is right.

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    Thank you for confirming

    parent root

    I’d say your mechanic friend is not right.

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  • The only issue I can think of is if the pads are worn really low then the pistons that have to cover the longer distance might be overextended out of the caliper. You can buy rotors with a different hat height to have the disc in a different location.

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  • Disc brakes auto-adjust to compensate for such things. That part of why calipers slide instead of being rigidly mounted.

    If it’s not rubbing, it’s fine.

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    What you described are floating calipers, which I have them on the rears. My fronts (in the picture) are fixed calipers. There are debates whether centering is necessary, but in my case it's offset to the right, shimming would not fix this issue...so annoying

    parent root

    Fixed calipers should always be centered. I would question if you could even fit a new set of pads in there as it is. Usually they’re too thick that if you’re offset that much you physically can’t fit them in there.

    Honestly sounds like you have incorrect rotors if the old one lines up correct and this doesn’t.

    parent root

    Weirdly new pads fits fine. I'm wondering if the thickness of the rotor is not right...this is just too much work lol

    parent root

    If the pads fit fine, you can run it. You likely won't see many issues on a street vehicle, but if you have shims that's the best way to center it. Usually doesn't take much.

    The rotor could have a slightly different offset. I'd double check it's the correct part for your car. Usually they'll line up dead on with the OEM ones.

    parent root

    How would shimming not fix the issue? You shim the brake caliper where it mounts to the knuckle, so that it sits farther inwards, which would bring the rotor more center.

    parent root

    It won't, this is the front left caliper, and the caliper bolts to the left side of the hub. So shimming will bring the caliper more outward instead of inward

    parent root

    That's weird. Fixed calipers are usually made to be shimmed so that they always adjust the correct way and avoid this situation

    Where did you get the parts? Rotor is correct and installed correctly? What does instruction manual and manufacturer say?

    If it all checks out and you have a mechanic friend check your work, then ok - you have a bit of misalignment - but iirc it can't be more than a couple hundreths maybe less

    Tl;dr try not to mess up brake work

    parent root

    Sorry, didn’t see the details of the calipers… when there are pistons on both sides, they accommodate the adjustments, allowing the caliper to be fixed.

    Same thing just a different mechanism.

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