ABS cutting in at very low speeds

[simon worthy]

i have a 500sl auto, 126 chassis 1990, the brake pads and discs have recently been replaced and i still have a very annoying problem.

at very low speeds then ABS cuts in and causes a stuttering of the brakes.

we were suggested to try it in neutral and this makes no difference.

has anyone got an idea, will it mean a trip to a main dealer or someone with a diagnostic machine or shall a now go ahead with replacing the abs sensors?

 

[stwat]

Has one of the sensors been dislodged when the disks and pads were replaced? While your checking this i recommend you clean the sensors with brake cleaner.

Hope this helps and let us know how you get on.

Stu

 

[simon worthy]

thanks for reply, but we have had the fault since buying the car, we hoped the brake change would cure it and so did the fitter as he thought he would find a cracked cog , but both were fine and after cleaning still no better

 

[stwat]

Having just looked at my manual, Its a very complex system which needs looking at by someone who knows about the system TBH. (lots of valves, solenoid exhaust valves, solenoid inlet valves, silencers, ect, ect!!!!!!!



Stu

 

[justino]

I too have the same problem. Having read up on this the easiest solution seems to be to clean the sensors, but this has not worked for me.

My 2 front sensors have a small 'tip' a little like a screwdriver bit. The rear one in the diff has no such tip. Does anybody know if the rear sensor has a tip like the fronts, if so looks like mine is warn and may be the culprit.

For info I have a 4matic. The 4 wheel drive doesn't appear to work, but I have no warning lights, so I'm hoping a duff rear sensor is also stopping the 4 wheel drive working. My rear diff also locks up a slow speed, again this points to an abs sensor problem due to it not being able to compare the front and rear wheel speeds correctly.

All other times the ABS works fine, worst I get from a quick stop is a 'chirp' from the front tyres as they are on the point of locking up.

 

[paulcallender]

Looking at previous posts, others have solved this by finding that the wire to the sensor was trapped under something and broken. It could also be different size tyres - the ABS system is sensitive to this. It somertimes occurs in older cars as owners are more inclined to replace tyres one by one.

 

[richybeattie]

I've had my 190e 2.0 since May 05 and have recently had the very same problem described. I've had brakes checked as ok and then the abs system. Only thing wrong was the abs sensors being covered in muck. Since they have been cleaned, the stuttering has disappeared..

but.....

..I can still here a, well, what I can only describe as a very distant chain saw revving for a couple of seconds when I first pull away.

I'm certain the stuttering will reappear, I can feel the nervousness through the pedal. I've spoken to the previous owner (from new) and he said that he had the same problem from about 95 and all the mercedes benz mechanics in the UK couldn't get to the bottom of it.

Maybe it's just one of those 190e querks I'm learning to love?!