'86 190E 2.3 - rear brakes dragging
 

My rear brakes keep dragging but not locking up. It puts a stain on the acceleration, transmission, waste gas and I can smell the brakes sometimes. I've stopped driving it for the moment.

This happens once the car gets warmed up and tends to happen more in warmer weather. This satrted to happen when the motor was overheating due to a faulty water pump. Could it be the ABS unit or the relay ABS motor? A caliper disfunction?

Doing my homework by reading related posts.

Gregorio
Monterrey, Mexico
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1986 190E 2.3
1960 190 B

if your brake is dragging, it can overheat and damage your wheel bearing. After driving it, feel for any difference in built-up heat of your left and right rear wheels.

When cold and the engine off, and you spin the rear tires by hand are the brakes dragging or do the wheels spin freely? My first reaction is that you may need to replace the rear calipers. Old flexible brake lines can swell internally and cause brakes to remain on after the pedal is released but usually they release after a few seconds. Check the pads and rotors and make sure they are not cracked and hanging up. I'm not familar with ABS problems.

Calipers are about $70 each and easy to replace.

dragging brakes
 

Thank you bobbyv and Robby I will try both of your advice once I get it back. I let you know how it goes.

Gregorio
Monterrey, Mexico
__________________

1986 190E 2.3
1960 190 B

When was the last time the brakes were bled?

If you are going to take the wheels off. Try carefully pushing the brake pucks back into the calipers. Try to do this several times.

I used to work with a factory trained Porsche tech who always did this on all four corners at major maintenances, whether brake pads were need or not. He said it cleaned and lubed the pucks.

It might temporarily helped a stuck puck.

Haasman

follow-up on dragging brakes
 

As it turns out it's the rubber rings which can be replaced with a caliper kit front and rear. The Laredo MB dealer sells only the whole caliper and AutoZone is a special order.

Bobbyv there wasn't a difference in built-up heat of your left and right rear wheels or even the front wheels. They were all the same hot temperature after dragging.

Robby the pads and rotors were not cracked and hung up but because of the dragging wear I had to replace the rear brakes. And I didn't try to spin the wheels freely yet.

Haasman,

I asked the mechanic to change the brake fluid (and bleed the brakes) but they didn't do this.
You say: "Try carefully pushing the brake pucks back into the calipers. Try to do this several times." I will ask the mechanic to do this.

Gregorio
Monterrey, Mexico
__________________

1986 190E 2.3
1960 190 B

Gregorio

thanks for the update. It will be intesting so see what solves this braking problem!

Mercedes-Benz, Los mejores coches del mundo! Guárdenos se puso al día.

Haasman

Probably already checked but...
 

Are you sure it is not your emergency brake pads?:confused:

I'd have to say the symptoms sound exactly like old brake fluid with air and/or water contamination. It would not be a bad idea at this stage to replace the piston seals (I think that is what you were referring to), since all rubber parts will deteriorate in brake fluid that is old. Still, the seals themselves will not likely cause your problem - you need a complete system flush, and this also should involve an inspection of front brake calipers and possibly master cylinder if the fluid is really grungy.

Steve