ABS wheel sensors [Archive] - Diesel Place : Chevrolet and GMC Diesel Truck Forums

: ABS wheel sensors


George_CPA
08-02-2008, 09:33 AM
I have a 04' 2500. I just recently replaced both front and rear rotors and brakes. Yes I followed the instructions posted here on this site to the letter. Pads slide nicely.

I believe my problem is in the wheel speed sensors. I pulled one out to examine it and it was clean as a whistle. Is there a way to test them with a meter? I was told when you spin the wheel you should read 350 mv/dc. My Fluke doesn't have mv/dc only mv/ac.

I had the local service manager take it for a ride and he suspects that is the problem. When you push the pedal it starts to stop, just as you are about to stop the pedal creeps down another inch.

TIA
George

ski
08-02-2008, 07:46 PM
Do the anti lock brakes kick in right when your about to stop?
I had that problem & replaced both sensors. Got them off ebay for about $40 a piece. It fixed my problem.

blizzardplowman
08-13-2008, 11:08 PM
Do the anti lock brakes kick in right when your about to stop?
That fits mine almost to the t, the only other thing I have is a "squeak" when coming to a stop in addition to the pulse, new roters and brakes about 8k ago on all 4 corners. Any thoughts? This is on the 01

heymccall
08-13-2008, 11:28 PM
Typically, when you get that ABS pulse just before stopping completely, one of the wheel speed sensors is too far away from the internal reluctor wheel.

When examining a sensor, you will note that there is a flag-type tab sticking to the side where the bolt goes through. Looking from the top, the entire profile of the sensor, including the flag, must rest on corrosion free metal. The problem you are experiencing is caused by that contact area raising the sensor outward, albeit slightly. Clean the resting area down to smooth and reinstall. As for the sensor itself, they are both still good if the ABS lamp remains OFF in the dash. A failed sensor will trigger the ABS lamp, improper clearance will not.

GM has a recall on many of the full-size trucks for just such a problem. They will do the same thing I described. Search "ABS Recall" for more info.

Also, with out the mv setting on your meter, simply measure resistance across the two terminals and verify that they are similar side to side.

As for the squeak, read post #7 here http://www.dieselplace.com/forum/showthread.php?t=146597&highlight=another+soft+brake and see if you did the brakes right, or if corrosion has occured since.

Whether the complaint is a soft pedal, noisy application, rotors wearing on one side, or premature front hub bearing failure, they are all related to corrosion in the foundation brake hardware.

George_CPA
08-14-2008, 09:55 PM
Thanks McCall!

I could remember having the same problem years ago, w/ another truck. I thought that was the solution but I needed to hear it from someone else.

Thanks again!