stuck Fr. Brake light switch

[Ogmios]

any ideas?
R100GS paralever.

front brake light switch is stuck ON.
the cause is not obvious (i'm good at obvious ).

symptoms -
the lever sits in approx 1/4" nearer the 'bar than it should.
so - the light switch thinks the brake is applied.

...as if the master cylinder pushrod confused: wotever its called that forces fluid along the line) that the lever pushes against is not returning to rest (fully out) - hence the brake light stays on.

nothing appears seized (in the cold and dark this evening) and IF the brake is binding - its very little.
i'll get a better look at it tomorrow / but hoped that someone among the collective would go...
"ahhh! - i know what that is!"

i wait in hope.
Cheers all.
TIA

 

[brassmonkey001]

Can you push the lever back to its proper position and if so, does it then turn off the brake light?

 

[Ogmios]

Can you push the lever back to its proper position and if so, does it then turn off the brake light?

yes. no problem....

 

[(RIP) pastyman]

I had the very same with my 80 g/s. I had renewed the brake line and also the master cylinder seals. When I got it all back together the brakes worked ok except that it felt a bit "wooden". and there was the play that you described with the brake light switch comming on.
After putting up with it for a while and pissing off everyone following me I decided to investigate. I took the master cylinder out again . It seemed that the end of the piston was not making contact with the nodule on the brake lever. after much head scratching, I delved into the area wher the m/cylinder seats in the housing. There was a large washer and a rubber grommet, It was clear that this was what was holding the cylinder out of position. The micro fiche diagram didnt help but with a bit of common sense and trial and error, I managed to fit everything together with minimal play at the lever and the brake light switch working as it should. Brakes also feel better.
Sooooo!. Have you had your s apart? if so check the rubber grommet /

 

[Ogmios]

Thank you!
that sounds about right
i shall look into my grommetry asap.
the symptoms sounds exactly the same.

but wil have to commute on the Guzzi tomorrow.... that'll be entertaining
and have a look at the weekend. *fingers crossed*

Ta!

 

[bimmerboxer]

Happened on my R100 as well, especially after I had changed the brake lines to steel braided ones.

Did the strip, clean, replace (seals) and bleed. Still spongy thus not returning back to place and leaving the brake light on.

Finally, a full brake fluid flush did the job, concluding that the was air somewhere up there.

Hope this helps.

 

[Rob Farmer]

Talk about dragging up the past..4 years between posts