ABS brakes doing funny stuff, any ideas

KyRob · August 1, 2012

The abs brakes on my 04 sierra 4x4 start pulsating or whatever when I make a fairly sharp left turn while applying the brake at the same time. I only notice this when I turn into my driveway but it does it nearly every time. It does it on grass and gravel but the tire is slipping a bit on these surfaces I assume. The truck only has 54,000 miles on it. The front rotors look like a comb has went around them as they are not at all smooth. The rotors are new (10,000 miles ago) oem and the pads are mid grade parts house variety. A guy I work with said his did the abs thing and the wheel bearings were shot. I would hope to get more than 54,000 miles on wheel bearings. Also, I took the wheels off yesterday and the rotors pretty much just fell off. I figured they would be on pretty tight but they weren't. Any ideas what may be going on with all this?

Thanks,

Rob

txab · August 1, 2012

I'd certainly start by checking the wheel bearing form description. A bad bearing can throw the code. If you can get the code read, it might help you.

KyRob · August 2, 2012

I tried to move the tire/wheel left/right and up/down while I had it jacked up yesterday with no obvious movement in any direction. Not sure about the code cause nothing ever shows up anywhere. As a far out guess, right where I turn in to my drive there are a set of dozer tracks in the blacktop that are kinda like a rumble strip. I am wondering if this would cause it as I have never really had it happen on blacktop anywhere but in this one area but again, I have had the truck for 6 years and it just started a month or so ago but randomly . I am going to have to test this tomorrow by turning in my neighbors drive.

Thanks for the response,

Rob

waumo1 · August 2, 2012

Also, I took the wheels off yesterday and the rotors pretty much just fell off. I figured they would be on pretty tight but they weren't. Any ideas what may be going on with all this?

Thanks,

Rob

I assume you don't really mean the rotors actually fell off but that they are just loose and can move around? I don't think they can actually come off without removing the calipers? The wheel and lug nuts hold them tight to the hub when the wheel is on.

txab · August 2, 2012

I tried to move the tire/wheel left/right and up/down while I had it jacked up yesterday with no obvious movement in any direction. Not sure about the code cause nothing ever shows up anywhere. As a far out guess, right where I turn in to my drive there are a set of dozer tracks in the blacktop that are kinda like a rumble strip. I am wondering if this would cause it as I have never really had it happen on blacktop anywhere but in this one area but again, I have had the truck for 6 years and it just started a month or so ago but randomly . I am going to have to test this tomorrow by turning in my neighbors drive.

Thanks for the response,

Rob

My bad on the code. I thought I read you were getting ABS lights.

KyRob · August 2, 2012

It was after I took the caliper and pads off that the rotor just fell down onto the studs. It wasn't tight at all. First one I have ever seen do that. Usually have to use a BFH on them. I think I will get some ceramic pads and turn the rotors and see if that helps as they do need turned down. Are the ceramics better than the semi metallic? I assume that is what I have now as they hardly look worn at all but the rotors look awful.

Thanks,

Rob

waumo1 · August 2, 2012

It was after I took the caliper and pads off that the rotor just fell down onto the studs. It wasn't tight at all. First one I have ever seen do that. Usually have to use a BFH on them. I think I will get some ceramic pads and turn the rotors and see if that helps as they do need turned down. Are the ceramics better than the semi metallic? I assume that is what I have now as they hardly look worn at all but the rotors look awful.

Thanks,

Rob

I only every had a problem pulling the rotors off by hand if they rusted to the hub. You can put your lug nuts back on without the wheel to evaluate how the rotor lines up and if it is warped, etc.

Either the pads or rotor or both are going to wear. Soft pads wear down and other pads never wear but wear the rotor out.

My 98 K1500 pads only lasted 15K. I replaced with ceramic pads and then the rotor wore but the pads lasted until I got rid of the truck and they still looked almost new.