2000 Blazer LT 77,000 MI

In the last few months my brakes have been acting very strange. It is hard to describe: Like a pulsate..vibrate...grab?? when I go to stop. Sometimes along with this I hear what sounds like a motor or compresser kick on (in pedal area) just while I am applying the brakes. I am able to stop, but sometimes it feels for a split second like maybe I won't. Brakes look good/lines replaced/bleed. Anyone with ideas?
Thanks!

 

welp it sounds to me like you have a warped rotor!! dont do anything but have a brake job done the right way,make sure who ever does it make sure the rotors are turned which means that the rotors are cut... the abs braking is sensing that the brakes are getting low and that the fliud in the master cylinder is prob very low...

 

Is it at all speeds or just low speeds? Either way, check your ABS sensor wires. I had a pinched/severed speed sensor wire on my right front and the ABS would kick on at low speed stops. It could also be a dirty wheel speed sensor giving bad information and telling the ABS to turn on when it doesn't need to.

If you didn't also mention the "sounds like a motor or compressor kick on" then I would say just a warped rotor.

 

I'm trying to help a friend with the *exact* same problem.

Even when stopping extremely easily, the ABS will kick in just before the truck comes to a rest.

I just replaced a bad wheel bearing and it got a new sensor as well; however, I would think that if a sensor was getting a bad signal that the ABS light would be on, and that it would disable the ABS from working instead of making the ABS kick in all the time. This is what happens on VWs..but I'm good with them, not so good with the Blazers. Anyone else fixed this problem before?

 

The abs engaging while moving at slow speeds is often caused by a dirty reluctor ring which is what the sensor uses to determine the speed of the wheel. If the ring is dirty, it could work well at high speed, but low speed definition may be degraded, causing the engagement. Often all that is necessary is to remove the wheel speed sensor and clean the teeth on the reluctor ring through the hole, rotating the wheel to make sure you get all of the teeth clean.

 

It is at very low speeds just right before the car comes to a complete stop. The light has never come on and the motor noise doesn't always come on either. Where is the reluctor located? Is it something anyone can do?

 

Its in the hub assembly where the speed sensor goes into if its what im thinking it is. You should be able to clean the sensor off. I disagree with the comment about turning rotor in a brake job if they are warrped you will most likely just make it worse by making them thin. Plus for the price of decent rotors you might as well buy them and save yourself turning them and then having to get new ones a month later.

 

I had the exact same problem with my 2000. Pull the fuse for the ABS (I think it is #22) from the fuse panel on the left side of the dash when the drivers door is opened. The ABS light will be on and the cruise control might not work, but if your problem goes away with the fuse out it is probably the front wheel speed sensors. There's a bunch of info about this on this site about how to fix this - it's a common problem.