97 anti lock brakes engaging just before stopping

[4minc]

I have a 1997 Z-71 Sierra. Just before coming to a complete stop the antilock brakes will engage for no reason (on dry pavement) making . Problem is getting worse. Any ideas? Are these 4 wheel anti lock?
Thanks

[2000CAYukon]

First step would be to clean the wheel speed sensors and reluctor rings on the front wheels. You need to remove the rotors to do this.

//2000CAYukon

[tempfixit]

2000 Yukon when you say reluctor ring on the front wheels are you speaking of the ring inside the hub assembly and if so what is the best way to clean the ring??

Thanks for all advice

[2000CAYukon]

Look at the post from GMMerlin in this thread: http://www.automotiveforums.com/vbul...t=abs+reluctor

//2000CAYukon

[tempfixit]

Thanks 2000CAYukon, very informational thread. Will check and clean when weather permits.

[4minc]

Originally Posted by 2000CAYukon

First step would be to clean the wheel speed sensors and reluctor rings on the front wheels. You need to remove the rotors to do this.

//2000CAYukon

Does anybody have a picture of the speed sensor. When I had my wheel off I only found one wire going into the hub with an allen bolt holding it in. Location of this wire is about 10 o'clock on the hub. IS this the sensor or something else? I looked at a new hub at the parts store and it came with this piece. If this is not the sensor, where is it located?
Thanks

[tempfixit]

Originally Posted by 4minc

Does anybody have a picture of the speed sensor. When I had my wheel off I only found one wire going into the hub with an allen bolt holding it in. Location of this wire is about 10 o'clock on the hub. IS this the sensor or something else? I looked at a new hub at the parts store and it came with this piece. If this is not the sensor, where is it located?
Thanks

Here is link that shows the sensor and wire: http://www.partsamerica.com/ProductL...S+Wheel+Sensor

To answer your question, YES that is the wheel speed sensor. Remove allen screw and gently pull upwards to remove. Clean rust off of the hub with a wire brush (Make sure you plug the hole where the sensor came out of so you do not contaminate the inside of the hub). Clean the sensor also. Apply a film of grease to sensor, sensor o-ring, and top of hub where sensor goes and re-install.

Good Luck

[wafrederick]

Cleaning the speed sensor will not fix it sometimes and will break off in the wheelbearing sometimes.If this happens,a trip to the dealer with a $100.00 bill plus tax.It could be the wheelbearing too,this happened to my father's 2002 GMC Dually.It was the left wheelbearing and it went away after a test drive right after replacing the left side wheelbearing.

[4minc]

Originally Posted by wafrederick

Cleaning the speed sensor will not fix it sometimes and will break off in the wheelbearing sometimes.If this happens,a trip to the dealer with a $100.00 bill plus tax.It could be the wheelbearing too,this happened to my father's 2002 GMC Dually.It was the left wheelbearing and it went away after a test drive right after replacing the left side wheelbearing.

It was the speed sensor. I have only done the drivers side so far but it seems to have fixed the problem. The corrosion was actually on the hub itself, where the sensor interfaces to the hub. I scraped it with a screw driver and sandpappered it a little and problem solved. The hardest part of the job was getting the two bolts out that hold the shield in place. I ended up cutting one of them off!