I had a bad bearing and I replaced the front right wheel hub assembly today ($85 at NAPA for the unamerican part). The hub came with a new ABS wire that I routed along the brake line and plugged in to the connector. The new bearing works fine, but now the ABS activates under normal breaking! I've read a bunch of posts in the forum about cleaning dirty ABS sensors, but this is a new sensor on a new hub assembly. Any ideas or suggestions? I'm ready to pull the ABS fuse for now, as it would be safer breaking without the ABS going off all the time.

Crap![:@]

 

Could possibly be that the air gap between the sensor and the reluctor ring in the hub assembly is not correct. LCR (low cost region) parts being as they are, this is not unheard of.

 

There was a piece of paper in the box with the new hub assembly that said the old ABS wire would not work with the new hub, so I pulled the old ABS wire and used the new one that came with the hub assembly. I'm toying with the idea of connecting the old wire to the new hub, if it will fit properly, and see if that corrects the ABS problem.

Any ideas how I could close the gap on the new sensor For now I pulled the ABS fuse[&:].

 

To close up the gap, you must file down the surface the wheel speed sensor (ABS sensor) mounts to. You have to remove the sensor prior to filing the surface. You want to have an AC voltage output of at least 350mV-AC when turning the wheel by hand. First you should get the front end up on jack stands, disconnect the suspect WSS and observe the AC voltage by connecting a multi-meter onto the wires and spinning the wheel. If it is over 350mV-AC, then you have a problem somewhere else in the system. If not, then you have to file the mounting surface.

 

I had this problem after replacing the brake calipers, i got grease on one of the abs sensorsand burned the other one with and oxy act torch, i cleaned the one sensor and got a replacement for the burned one at my local junk yard for 3.00. i did notice polarity was an issue and i heard some aftermarket sensors used reverse plugs then certain oem wire harnesses once i hashed out the typical chevy wiring nightmarei havent had a problem since. my abs would act up id say about 65-80 percent of the time espically under hard stopping, i hope this helps

 

i am also having this problem. I tried testing the sensors with my DMM but i dont think it has the right setting. Here is one that is just like mine. What would i set it on. Also whenever i brake hard my brake light comes on and the fluid is full. I dont know if they are related or not.

 

Set it on ACV. Not sure if it will have the resolution necessary though...

 

Whenever I have messed with the abs wheel speed sensors i noticed a red lubrication or grease. I'm not sure but maybe you need a little grease in there for the contacts to work correctly?