I just picked up a 1997 Chevy Blazer 4x4 a few months back and this week it started developing a rotational squeal coming from the passenger front brakes. Today I took off brake pads hoping to find something, but the pads are in great shape with plenty of wear left before the pad wear indicator and the rotor looks brand new. I cleaned up the gear teeth on the back of the hub and noticed that I think the ABS sensor was touching the hub thread studs as I rotate the hub. It wasn't loud, but after I put everything back together after cleaning the rotational squeal was back and very annoying. I only hear it when braking and just after braking at low speeds until it gets up to speed and it goes away. Any ideas?

I've read on the forums that you can bend the ABS sensor plate away from the hub, but what I was looking at looked like a small aluminum cover on the acutal ABS sensor was touching the hub. Can you bend that?

Any help would be greatly appreciated. BTW, there was no noise from the CV joint when I was turning it and it was in 2WD, it all seemed to come from around the ABS sensor.

 

The ABS front wheel speed sensors, (2nd design) on 4WD are part of the hub/bearing assembly. The reluctor wheel teeth are not visible without removing the sensor. Can you post an image of what you're referring to?

Edit: The 1st design does use an external sensor.

 

I ended up fixing the rotational squeal. It was the cover plate over the ABS sensor. It somehow bent out and was rubbing on the hub. Now after the test drive to confirm I fixed it I ended up developing a crack in the rear brake line. Fluid all over my driveway...

 

When it comes time to bleed the system, gravity bleed it, don't pump the pedal. Make sure the master cylinder does not run dry.

 

+1 on that one Captn'