Hey everyone,

I am trying to get my 1987 300D (with a #22 head) a brake and light inspection since it was hit by a neighbors U-haul.

The problem is, I have an annoying "anti lock" light.

I've checked both front wheel sensors, cleaned them and flushed the brake fluid and the light doesn't come on as much anymore as it was before.

I can go up past 40mph and the light doesn't come on.

**Whenever I come to a stop at slower speeds I can feel the brake pedal pulsating.. no matter how many times I stop, I know this isn't right.**

When I try to brake from a higher speed or long slow application of the brake the light comes on.

I am a little stumped.

The parking brake pads are beyond worn. I read another thread said that could cause an issue.

I am looking for any recommendations of what this could be.

THANKS!

Dan

The easiest way would be to get an oscilloscope and look at the waveforms from the sensors. It sounds like one or more still aren't working right.

Are the tone rings clean? Nice sharp, non rusty edges?

Because the rear ABS sensor is inside the differential I can't see how the parking brakes could have anything to do with it.

Check out this thread: http://www.peachparts.com/shopforum/tech-help/288450-trying-troubleshooot-bosch-abs2.html

Annoyingly the ABS system has extremely limited diagnostic capability. It can throw the light when it thinks something is really wrong, but it has no built in way to tell you what sensor is bad. (Unlike other modules in the car that can give you blink error codes).

-J

__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Thank you for your response and tips!

I checked the tone ring on the passenger side today, it didn't look extremely gunked up, but it didn't look shiny clean either, maybe even a little rusty. Maybe I'll try cleaning it. I will check the drivers side tomorrow. Definitely noticed a difference in the abs light coming on when I flushed the brake system.

an oscilloscope sounds handy, but I wonder how much they cost. I know before I tested the sensor by lifting the driver and passenger side of the car starting the engine and spinning each wheel independently (I had read this was a way to check the sensors) The driver side wheel set the anti lock light almost immediately upon rotation. So I got a few sensors out of pick n pull but with all 3 I tried new sensor it still set the light.

I will probably look into that better. The passenger side front tire turned didn't ever set the light off.

I know it is probably lazy, but if it didn't have to pass brake and light test I wouldn't bother with it at all! haha.

I feel like I am getting closer to getting this done, with each attempt I've made it gets a little better.