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  #1  
Old 10-30-2007, 07:28 PM
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W124 brake-pad light question

Hello everyone. The brake-pad light on my 1993 300E recently came on. I assumed this just meant it was time for new pads, but after poking around on here it sounds like the light is supposed to come on only when the brakes are being used. Is this correct? Well, I ask because the light on my car is coming on right after the car is started and the brake pedal isn't being touched, and comes on sometimes while driving (it'll come on and off while driving on the highway, for instance).

Any ideas what might be causing this?

Thanks,
Mike
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  #2  
Old 10-30-2007, 09:12 PM
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If the little nubs are worn down, it could possibly be touching all the time. Or there is a short somewhere. It is the brake wear indicator light, and not the other brake light, correct? (If you're not 100% sure, check your brake fluid)
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  #3  
Old 10-30-2007, 09:23 PM
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You have ground the wear sensors down to bare metal.. You need brakes. This is something you need to address very soon.
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  #4  
Old 10-30-2007, 09:33 PM
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is that the orange/yellow sun looking light ? i thought it was tire balance light

any links to wear sensors for sale
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  #5  
Old 10-30-2007, 10:30 PM
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There is no tire balance light
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  #6  
Old 10-30-2007, 10:34 PM
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Quote:
Originally Posted by Pete Geither View Post
You have ground the wear sensors down to bare metal.. You need brakes. This is something you need to address very soon.
The light just came on; I've driven probably 50 miles since the light first came on. Would this indicate it's a sensor issue and not a brake issue?
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  #7  
Old 10-30-2007, 10:35 PM
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Quote:
Originally Posted by Larry Delor View Post
If the little nubs are worn down, it could possibly be touching all the time. Or there is a short somewhere. It is the brake wear indicator light, and not the other brake light, correct? (If you're not 100% sure, check your brake fluid)
Yep, it's the circle with lines on each side, not the one that says "brake."
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  #8  
Old 10-30-2007, 10:36 PM
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Light for brakes comes on when it is grounded out, either by the pads being worn enough to allow the sensor to make contact to ground, or a break in the sensor wire etc causing a grounding of the sensor. Either way you need to pull the wheels and check the brake pads and sensors to see what the situation is. Either way you have something grounding the sensor system and it needs to be addressed either with finding the short or repalcing the sensors and brake pads.
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Old 10-30-2007, 10:40 PM
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Does anyone have an owner's manual??

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  #10  
Old 10-30-2007, 10:46 PM
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Quote:
Originally Posted by crhenkel View Post
Light for brakes comes on when it is grounded out, either by the pads being worn enough to allow the sensor to make contact to ground, or a break in the sensor wire etc causing a grounding of the sensor. Either way you need to pull the wheels and check the brake pads and sensors to see what the situation is. Either way you have something grounding the sensor system and it needs to be addressed either with finding the short or repalcing the sensors and brake pads.
Thanks. I'm not sure whether to keep my fingers crossed that it's the pads or a sensor issue.
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  #11  
Old 10-30-2007, 11:41 PM
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Either is an easy fix...pads are cheap and the sensors are about $4 each. If the pads are even close to worn and you have to do new sensors, do pads to to be done with it. If you need pads, always replace the sensors, they are cheap and should be kept in working condition.
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  #12  
Old 10-31-2007, 12:08 AM
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cool i found the sensor for 1 dollar .. ill add it to my little parts list ... mine comes on every now and then .. i alwys thought it was my wheel balance since i roasted the tread off my back wheels
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  #13  
Old 10-31-2007, 01:30 AM
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I am not sure but wont that come on if the brake fluid gets low also.
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  #14  
Old 10-31-2007, 11:46 AM
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The "skinny" on brake indicators...

The yellow "sun-looking" indicator is actually supposed to be a universal representation of either brake drum configurations of the past or perhaps a caliper/rotor icon...either way, it is simply the mechanism that tells you that your pads are due for replacing.

The sensor "grounds" itself when it comes in contact with the rotor , thus setting off the light. Even on cold start mornings before you even apply the brakes, the light may come on (consider that your pads are ALWAYS in contact with the rotors anyway). During the rest of the trip, the light flickers rapidly depending on the vehicle speed as you apply the brakes.

Any other brake related issue will set off the RED brake light indicator...low brake fluid, low brake pressure, or complete brake failure. This is a circle with a "B" in the middle. Again, it is red.

Unless you go shalom racing on weekends frequently, the pad wear indicator gives you PLENTY of time to address the issue. I went nearly two months under normal city/highway driving conditions (avg. 45 mi/day) before I pulled mine off...and they still had 30% of the meat left on the pads!

Before you go out and buy sensors, consider that most pad replacements kits already come with sensors included. Make sure you check with the parts guy at FastLane when you do. I am assuming you will purchase them here...you won't be dissapointed!

And W124s only have front pad wear sensors. You will have to inspect your rears visually to determine if they also need replacement. They don't take the brunt of the stopping force, so generally I find that they require replacement every other time I replace the fronts.
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  #15  
Old 10-31-2007, 11:53 AM
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YES< What G-Benz said. He cleared up what the rest of up were trying to say. Good explaination
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