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2019 Slim Brake light sticking

  • Mesmer
    Mesmer
    1 year ago
    Hi there guys, this may, or may not, have been asked before but here goes: 2019 Slim has a sticking front brake light switch. I only noticed it because the cruise control refused to engage. I have a feeling that the switch itself is probably ok as I can pull the brake on and then allow the lever to "flick" forward and the light will go out. So, I'm thinking that it might be the piston that's sticking.

    I know this was common on older machines but I've not come across this on an M8.

    Anyone got suggestions for a fix? Is there much involved disassembling the lever and unit to grease the exposed piston end?

    Much appreciated

  • STEAMER
    STEAMER
    1 year ago
    Quoting Mesmer on 21 May 2022 06:20 PM

    Hi there guys, this may, or may not, have been asked before but here goes: 2019 Slim has a sticking front brake light switch. I only noticed it because the cruise control refused to engage. I have a feeling that the switch itself is probably ok as I can pull the brake on and then allow the lever to "flick" forward and the light will go out. So, I'm thinking that it might be the piston that's sticking.

    I know this was common on older machines but I've not come across this on an M8.


    Anyone got suggestions for a fix? Is there much involved disassembling the lever and unit to grease the exposed piston end?

    Much appreciated

    Have the grips been changed,?  As there is a micro switch up at front brake lever on bars, that if not treated carefully it can also stop the brake light from working via front lever.  So in thinking that,  it might be sticking or caught on something causing it to keep brake light on. 
  • Mesmer
    Mesmer
    1 year ago
    Quoting Mesmer on 21 May 2022 06:20 PM

    Hi there guys, this may, or may not, have been asked before but here goes: 2019 Slim has a sticking front brake light switch. I only noticed it because the cruise control refused to engage. I have a feeling that the switch itself is probably ok as I can pull the brake on and then allow the lever to "flick" forward and the light will go out. So, I'm thinking that it might be the piston that's sticking.

    I know this was common on older machines but I've not come across this on an M8.


    Anyone got suggestions for a fix? Is there much involved disassembling the lever and unit to grease the exposed piston end?

    Much appreciated

    Quoting STEAMER on 21 May 2022 09:26 PM

    Have the grips been changed,?  As there is a micro switch up at front brake lever on bars, that if not treated carefully it can also stop the brake light from working via front lever.  So in thinking that,  it might be sticking or caught on something causing it to keep brake light on. 

    No, standard grips, nothing changed at all. It's so frustrating, this only happened after it had been into the dealer for it's annual service. The weather is pretty bad here at the moment which will give me an excuse to spend a bit of time to strip the lever assembly and see if there's anything sticking. I'm thinking it might be the master cylinder piston that's sticking and not returning to push the lever back out. We shall see!
  • wadewilson
    wadewilson
    1 year ago
    Just thinking out loud but if the master piston was sticking would this give pressure in the brake system and in turn cause the pads to be rubbing on the discs? If this is the case could this be tested by simply going for a ride then carefully touching one of the discs when you stop to check for any excessive heat build up.

    Perhaps this could also be felt as slop or free-play in the first few millimeters of travel in the brake lever. Maybe this is so imperceptible that you cannot feel it while riding with gloves on???

    Either way hope you work it out.
  • STROPP
    STROPP
    1 year ago
    Quoting Mesmer on 21 May 2022 06:20 PM

    Hi there guys, this may, or may not, have been asked before but here goes: 2019 Slim has a sticking front brake light switch. I only noticed it because the cruise control refused to engage. I have a feeling that the switch itself is probably ok as I can pull the brake on and then allow the lever to "flick" forward and the light will go out. So, I'm thinking that it might be the piston that's sticking.

    I know this was common on older machines but I've not come across this on an M8.


    Anyone got suggestions for a fix? Is there much involved disassembling the lever and unit to grease the exposed piston end?

    Much appreciated

    Quoting STEAMER on 21 May 2022 09:26 PM

    Have the grips been changed,?  As there is a micro switch up at front brake lever on bars, that if not treated carefully it can also stop the brake light from working via front lever.  So in thinking that,  it might be sticking or caught on something causing it to keep brake light on. 

    Quoting Mesmer on 22 May 2022 11:04 AM

    No, standard grips, nothing changed at all. It's so frustrating, this only happened after it had been into the dealer for it's annual service. The weather is pretty bad here at the moment which will give me an excuse to spend a bit of time to strip the lever assembly and see if there's anything sticking. I'm thinking it might be the master cylinder piston that's sticking and not returning to push the lever back out. We shall see!

    That is what it will be, fairly common with any hd model, need to pull it apart and check