HI, I have a 98 blazer 4d. Last summer (2010) I replaced front and back brakes and rotors along with both front hub and bearing assemblies. A few weeks after changing the hub & bearing my ABS light came on. I checked the plugs in both front wheel wells that I disconnected to change the assembly and they both seemed fully seated.

The ABS would usually pulsate and increase stopping distance upon first braking once per each time I started the vehicle. Although this was slightly dangerous and annoying I lived with it since I was unable to figure it out and became too busy to troubleshoot it. A few weeks ago I changed my back brakes which were completely gone. I don't drive the truck too much and only changed them 18 months ago, also the front, which I changed at the same time had plenty of pad left. So apparently my rear brakes had been engaged slightly to cause pre-mature wearing without it being engaged enough for me to notice.

Well, right after changing the rear brakes I now have excessive rubbing, squealing and the brakes are definitely engaged more than before. Now I can feel the resistance.
Any input on this or anyone with a similar problem? I haven't had the ABS checked, but I'm wondering if I bought a B & H assembly that had a bad sensor, but how does that engage the back brakes? What other components could I check? Thanks

 

I was able to get an OBDII CAN & ABS scanner for a few minutes, found 4 codes. C0281 - stop lamp switch circuit, C0223 - right front wheel speed signal erratic, C0221 - right front wheel speed sensor circuit open & C0265 - EBCM motor relay circuit.

I checked the right front wheel sensor plug and wires going into the plug from the frame and the sensor side. All seemed ok. I checked the brake pedal to see if there was excess play and to make sure it was engaging properly. After connecting and re-connecting the speed sensor plug and driving around 2 serparate times I no longer get the pulsating ABS but the light still is triggered. Possibly the speed sensor problem has been corrected but the other 2 remain. I don't have the scanner anymore to check.

Does anyone have any ideas as to why both back brakes would be engaging? Some times its slight and other times the brakes are providing noticeable resistance. It's not likely that both calipers went bad at the same time. Could the EBCM code have something to do with it? It must be something that the they have in common because there is only one brake line to the back that splits at the axle. Someone suggested that the rubber hose going from the frame to the axle could be have the inner tube pinched.

 

its not your sensors. its your EBCM and the only way to fix it is to either replace or rebuild. i had the same situation going on w/my blazer. check the thread below for the fix if you haven't done it yet.

https://blazerforum.com/forum/2nd-ge...y-hayes-55462/

also, i read your post and i had the same problem too. both lights on and the brakes were as it seems always engaged before i fixed the module. the truck can't move w/transmission engaged and foot off brakes on a flat surface. driving it felt like something was holding the wheels. its funny because after i fixed it car rolls freely when engaged on D or R without having to push gas pedal. also, it rolls down the street very smoothly. well, good luck to you!