Yes. I had the original master cylinder totally apart and if I remember correctly there is a 2nd smaller bore with a piston that has a notch that causes the switch to move back or forward sort of like a toggle. I ended up with a new or rebuilt master cylinder but I think I reused the electric switch. That may be the issue. No idea if it is available. When this subject came up I wondered if I might also have a switch on the brake pedal too.
Sent from my Galaxy Tab® A -------- Original message --------From: Max Dillon via Mercedes <mercedes@okiebenz.com> Date: 2017-01-18 6:17 PM (GMT-06:00) To: Mercedes Discussion List <mercedes@okiebenz.com> Cc: Max Dillon <dillonm...@gmail.com> Subject: Re: [MBZ] Brake Light on (was Best Axle Choice) If I recall correctly, Randy has brought up this issue before. His car's master cylinder has an extra sensor for the front-rear circuit's pressure differential, and that is the warning light. -- Max Dillon Charleston SC '87 300TD '95 E300 On January 18, 2017 4:11:01 PM EST, MG via Mercedes <mercedes@okiebenz.com> wrote: >It is probably connected to the parking brake warning switch, >(doesn't need much for the peddle to keep the switch closed. 1/4" >or so is enough) and in the 123s at least it also connects to the >reservoir level sensor. Pressing on the button on the top of the >reservoir will turn on the light. Sometimes the level float or >the button test contacts get stuck in the on position. Might >check that possibility if yours has that. > >Manfred > >Randy Bennell via Mercedes wrote: >> I appear to have triggered it a few years back when I decided to put >new >> brake fluid in and bled the brakes to clear the old fluid out. >> I could not get the light to go out after and thought that maybe the >> trigger to it had become stuck in the master cylinder since opening >the >> bleed screw and applying brake pressure woudl be similar to a failed >> line etc. >> I subsequently ( a couple of years later) suffered a failure of the >> master cylinder and replaced it. Still cannot get the brake light to >go >> out despite careful cleaning of the resevoir etc. Figure it is likely > >> something that has gone wrong with the switch on the master cylinder >but >> have not chased it. Just unplugged the wire so I do not have to see >the >> red light all the time. >> When I read that it might relate to the brake pedal mechanism on a >later >> model, I wondered if it might be similar on the earlier model. >> >> RB >> >> On 18/01/2017 11:20 AM, MG via Mercedes wrote: >>> Not familiar with those but if it is a sensor in the side of the >>> Master cylinder bore then it could be trying to tell you that one of > >>> your brake circuits isn't working. Probably the rear. >>> >>> Randy Bennell via Mercedes wrote: >>>> Does anyone know if this would apply to a 115? My brake light will >>>> not go out either. I have got the light out by pulling the wire on >>>> the side of the master cylinder. >>>> >>>> RB >>>> >>>> On 16/01/2017 9:42 PM, MG via Mercedes wrote: >>>>> I do believe that red light also lights up when the brake fluid is > >>>>> low. So you might want to check that or the sensor there. >Sometimes >>>>> the parking brake doesn't come up all the way if it wasn't oiled >for >>>>> a while. Might want to pull up on the peddle and see if that is >it. >>>>> >>>>> Manfred >>>>> >>>>> clay via Mercedes wrote: >>>>>> OOO On that note. Anybody able to point me toward the parking >>>>>> brake sensor? While swapping in LCD cluster lights, I put in a >>>>>> working bulb where the parking brake indicator lived. Now the >>>>>> light stays lit and will not go out even when the parking brake >is >>>>>> off. W126 SDL >>>>>> >>>>>> clay >>>>>> >>>>>> >>>>>> >>>>>>> On Jan 14, 2017, at 5:58 AM, Max Dillon via Mercedes >>>>>>> <mercedes@okiebenz.com> wrote: >>>>>>> >>>>>>> Don't forget the parking brake pads. Rear rotor has a small >drum >>>>>>> in center, parking brake assembly inside the drum. >>>>>>> -- >>>>>>> Max Dillon >>>> >>>> >>>> _______________________________________ >> >> >> _______________________________________ >> http://www.okiebenz.com >> >> To search list archives http://www.okiebenz.com/archive/ >> >> To Unsubscribe or change delivery options go to: >> http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com >> >> > >_______________________________________ >http://www.okiebenz.com > >To search list archives http://www.okiebenz.com/archive/ > >To Unsubscribe or change delivery options go to: >http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
