190E Braking System

gary_killington

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Joined
Nov 8, 2003
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1
Location
Ilford, Essex
Car
Mercedes 190E
I have a 1989 190E 2.0 manual. Just recently, I've experienced a problem where the brakes lock up intermittently, and I have to stop the car for a while for it to get over the problem. It seems to happen when I'm sitting in traffic, and the brake pedal gets higher and higher. I had the car tested on a rolling road, and it seems that when the fault occurs, my front brakes are OK, but the rear brakes don't work at all.

It's been suggested that I replace the "compensator valve". Does anybody know (a) if this sounds like the probable fault and (b) where can I find this valve?

Any help would be much appreciated.

Gary
 

Ian B Walker

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Jun 7, 2003
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Freckleton
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300-24, saloon and coupe, E300 24 valve diesel estate
Gary, do you by any chance have ABS fitted? If you do check to make sure your brake fluid is clean as dirty fluid sometimes forces the brakes to play up
 

scotth_uk

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May 16, 2003
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Sydney
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Renault
From memory the compensator valve is a device that controls the front/back braking force. As the car leans forward, it is supposed to give more braking to the back. At least this is the way that it worked on another car I had.

Very possible that it is malfunctioning and is applying all pressure to the front.

I would suggest a full brake bleed with the appropriate tools. Clean the entire system out and replace - won't cost much and will be very interesting to see if you can get anything from the back.
 

jimmy

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The brake compensator/regulator/load valve works similiar to what Scott has said.

A cars braking circuit is split so that the braking effort is roughly 60/40 with more effort applied to the front brakes. As you brake the weight shifts towards the front of the car and away from the rear wheels, this valve then lessens the braking force to the rear wheels to prevent them skidding.

You see these valves alot on vans and trucks, they are usually mounted near the rear axle. A fully laden van or truck can have more braking effort applied to the rear wheels than an unladen one.

I think cars with ABS dont have these valves, it is controlled electronically by measuring the speed of each wheel.

These valves are a common service item on some cars, they usually seize or the seals go on them.
 

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