OK...had the MC changed and system bled at a shop. Same problem. Mechanic won't release the car back to me because now that they have touched it they have liability issues. So they are pursuing the problem through their tech net. Hopefully will get to the bottom of this....

 

OK. Got my Blazer back after signing a release of liability with the shop. Tried pulling the ABS fuse and have the EXACT SAME SYMPTOMS!!! So much for the standard "false ABS application" fix that I finally found out about in another thread on this site. So... Still low speed only. Happens after making a sharp turn almost always and some times when going straight. New brakes. New hoses. New master cylinder. Completer brake fluid change and bleeding. ABS fuse removed.

Something I have noticed lately tho is when the brakes are on the floor with the wheels straight. If I keep pressure on the peddle and turn the wheels to one side or the other, the brake peddle hardens up and pushes against my foot and comes up a few inches.

Another symptom. Any thoughts on this one???

Thanks.

 

Following (because this is something I'd like to know how to fix if it every happened to me).

The only thing I could add is that I've done some thinking about the parking brakes and the circuit that overrides the daytime running lights (DRLs). Have you done any servicing on the parking brake pads? My understanding of the switch is that it is a simile contact switch so that its indicator light coming on or not could indicate something with the parking brake cable adjustment. BTW, the parking brake cable adjustment is separate from the parking brake shoe adjustment. That has to be done at the rear axle. I am familiar with the 4-wheel disk brakes system with the parking brake shoes on the inside of the rear rotors.

 

I had to adjust the parking brakes at the rear axle a while back. Not really sure how you are relating these two items together as far as the brake fade. I don't quite get what you are trying to say about the parking brake light switch. Can't remember if the brake fade started prior to this.

 

Is there another fuse for ABS besides the 60amp one under the hood?

 

OK, Back here again. Was recently told that the only way to ensure that the ABS system was completely disabled was to disconnect all the wheel sensors. So, I disconnected the front two but found no wires leading to the rear wheels. This is a 2001 Zr2 Blazer. Are there supposed to be ABS sensors in the rear and where are the wires located??? Still fighting this,,,

 

I only have abs sensors on my front wheels on my 1999 LT 4dr

 

I have a similar brake issue that i have not been able to figure out with my 2002 blazer 2wd. One moment the pedal is nice and high and the next time i press it it will almost go to the floor and the dash brake light will come on.
In the course of trying to fix my issue i have installed all new pads on all 4 corners, new front rotors, all 5 new hoses, new master cylinder, new hubs with new front sensors and zero leaks on any hard brake lines. I have bled it every way possible including the ABS and still have the intermittent issue.
My next attempt will be a new Delco master cylinder since the one i installed is an Autozone brand one. if that doesnt work then i may just throw a new set of calipers on it. I hate just throwing parts at it, but there is not much left on mine that has not already been changed and ive run out of ideas.

Also I dont believe you can unhook all ABS sensors, because i believe the rears use the speed sensor in the trans and if you disconnect that it will cause transmission shifting issues.

 

Any idea what wire to look for for the transmission speed sensor? My problem only happens at low speeds so I wont have to worry too much about transmission shifting. What has been labeled as a "false ABS aplication". There is a long thread about that here. Seems cleaning and re gapping the front sensors solves many of the problems.

 

The speed sensor on the 4l60e transmissions is in the tail housing on the passenger side.

Can you feel the ABS activating? Its a bit violent on these and you will hear the ABS module and feel it in the pedal when it activates.

On mine it is definitely not the ABS activating. I just get a very soft pedal. The first time it happened on mine was at the end of a drag run at about 105 MPH and it made my butt pucker up some.

If it is your ABS activating, i have seen the ABS act funky on these when the front hubs start going bad also. How new are your front hubs or how many miles on them?