Measuring Brake Disc Run-out?

Rishi

Platinum Member
So I have a steering judder under braking @ 30mph, when I brake from 50-60mph it's pretty much fine but as soon as I hit 30mph the steering wheel wobbles considerably. If i pull the handbrake up it's fine so I'm fairly sure it's the front brakes.

I changed my brakes all round a couple months back and everything was fine, then after a 500 mile trip the judder under braking developed. I recently replaced the n/s wishbone as I've had a knocking noise for months (ball joint was knackered) and it solved the knock but not the judder, I'm thinking the ball joint issue perhaps affected the n/s brake disc.

I'm changing the leaking thermostat housing this weekend and going to strip the front brakes, measure the disc run-out, clean up the hubs a bit. I'm just wondering if anyone knows what the disc run-out tolerances are?

Cheers!