Strange brake shudder?

[RyleyMA61]

ok.... brakes used to shudder when first installed (sti 326mm rotors with z32 4 piston calipers)

put new rotors and pads on.... after about 1000kms it's starting to shudder again

can anyone confirm my suspicions of my calipers being mounted at an angle to the rotors theory?

when turning the rotor it spins smoothly but then "grabs" slightly at a certain point, and is then easy again....

[Pure_In_Sanity]

Worn wheel bearing, or damaged hub possibly??

[IN 05 NT]

agree with bearing issue, could also have warped the rotors? and hard hot lockups?

[RyleyMA61]

wheel bearings are virtually new...

no lockups, a few hard stops but that's it really...

strange groaning noise happens sometimes too, sometimes when hard braking? fuckin strange...

[Pure_In_Sanity]

Groaning noise sounds like it will be the disk hitting the caliper / backing plate. What brand are the disks? RDA's + 227rwkw + Winton is probably a mismatch

I would think that the caliper being mounted on a slight angle would wear the pads unevenly, but not neccesarily cause a shudder.

I'd be getting hold of a dial guage, mounting the base to the strut tube & measuring the runout of the disk. Then remove the disk & check for runout of the hub (Bit tricky, but should be able to run the needle just outboard of the studs.



Cheers
Phil

[allencr]

It would be nice if there was no run-out on the hub AND disk, and the caliper was parallel to the disk.

[Pure_In_Sanity]

Indeed, but it would not be shuddering if that was the case.