Antilock brake problem - PeachParts Mercedes-Benz Forum

iwannabenz · #1 06-17-2009, 05:12 PM

.....so I have spent about an hour or so each of the last 3 evenings on the search section looking for the particular brake issue that I am having, can find some similar, but none exactly the same, so here goes, hope someone can help. (I thought I had "struck gold" when I found the link for testing the sensors, but I did not know where to look for them on my car)

My 1985 380SL needed brakes, had a fellow (part-time mechanic, full-time farmer, too long a story to explain here) fix my brakes. New calipers all around, new rotors, new pads, new brake lines, new master cylinder. Brakes work fine now EXCEPT when the car is almost stopped (moving at ¼ to ½ mph) the antilocks kick in for the last 1-2 feet of forward motion. This is not a safety issue, as the car is stopping normally, but it is very irritating. The fellow that did the brakes said he knew that they did that, but that he didn’t know anything about the antilock system (another long story, don’t ask). The only thing that I can come up with is perhaps the antilock sensors have been damaged/misaligned/confused during the brake job. My problem is that I don’t know where they are, what they look like, or how to check them. Any ideas? The antilock light on the dash is NOT lit. Thanks.

LUVMBDiesels · #2 06-17-2009, 05:44 PM

It is probably the sensors. If the light is not coming on then the ABS system is working as it should. Take off the wheel and look at the caliper and rotor. There should be a sensor evident that looks like this

If there is metallic dirt on the sensor it could trip the ABS.

Clean them off and let us know what happens

iwannabenz · #3 06-17-2009, 05:48 PM

Will do, thanks.

emerydc8 · #4 06-17-2009, 10:24 PM

My brakes were doing the same thing--until I cleaned the sensors.

LUVMBDiesels · #5 06-18-2009, 08:05 AM

Quote:

Originally Posted by emerydc8

My brakes were doing the same thing--until I cleaned the sensors.

yeah, they get nasty with filings, don't they.

After I cleaned mine, the ABS light started lighting up. I then had to unplug and remove the computer and clean the contacts with electrical contact cleaner to bring the system back to 100%

iwannabenz · #6 06-18-2009, 08:31 PM

I have just had enough time to pull one front wheel, and am trying to determine where the sensor is on the caliper. Gotta get back at it, as I am working outside and it is getting dark, and I'm not at my best working by trouble light (as opposed to sunlight). Thanks all, I'll post my findings (and probably more questions)

d

iwannabenz · #7 06-25-2009, 07:43 PM

Okay, here's what I am looking at, but it does't look like the sensor in the previous reply. The two white wires are held in place by rubber fittings, I can pull them out, but what do I clean? Still puzzled, thanks.

Arthur Dalton · #8 06-25-2009, 08:16 PM

Those are pad wear sensors.

The ABS is a cable with a reluctor sensor on the end. Held with one mouinting bolt.

http://catalog.peachparts.com/ShopByVehicle.epc?q=1985-Mercedes--Benz-380sl-Brake&yearid=1985%40%401985&makeid=63%40%40MERCEDES+BENZ%40%40X&modelid=6256%3AMBC%7C1528%3AED%7C10000052%40%40380SL&catid=241658%40%40Brake&subcatid=241755@@ABS+Speed+Sensor&mode=PA

iwannabenz · #9 06-25-2009, 08:48 PM

Thanks Arthur, I'll keep looking.

Dan