Crap, glad your OK. When was the last time the system was flushed?
Front brake failure
Scary incident despite only doing 3-4mph! I had been riding for no more that 5 or 6 minutes with everything working fine... slowing down at a set of traffic light I was drifting to a stop when the car ahead tried to change lanes and suddenly stopped. I jammed on the front brake but nothing! The lever came all the way back to the bar! No where near hitting the other car but shocked all the same. Tried the brake again and now working.... sounds strange but it happened....
Anyone else experienced this?
BMW R1200 GS Triple black 2011.
BMW have suggested that with age the brake fluid gathers in the pipes and conceals and speculate that a solid bit passed through the master cylinder causing the issue. Have quoted for a new master but surely that won't stop the same again will it?
Any advice welcome.
Thanks
Anyone else experienced this?
BMW R1200 GS Triple black 2011.
BMW have suggested that with age the brake fluid gathers in the pipes and conceals and speculate that a solid bit passed through the master cylinder causing the issue. Have quoted for a new master but surely that won't stop the same again will it?
Any advice welcome.
Thanks
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There are only two scenarios that I can come up with that would do what you describe.
1) ABS software error, which would require energizing the ABS "enable" and "dump" valves inappropriately. Or a sensor error that makes the unit think that the front wheel is locked up when it is in fact rolling and that error persists all the way to a stop, making the ABS dump valve stay open the whole time.
2) There was excess space in front of one or both of the front calipers, so when you squeezed, the brake pads moved in, but the master did not have enough volume to push the brake pads into contact with the rotor. If the brakes worked fine shortly before this failure, than this couldn't be the cause.
I don't see how the dealer's scenario could work. The volume of fluid that is pushed back into the master cylinder when you release the brake is tiny. No way any solids could make it back, especially something large enough to push the master cylinder cup so far from the wall that you would get zero action in a panic stop. I've never seen solids in brake fluid, unless you have never changed it since 2011 or added an incompatible brake fluid.
To have the lever come back to the bar is a lot of fluid displacement. It had to go somewhere.
Only other idea is a crack in the caliper/hardline/ABS body that is opening when the pressure gets high enough.
What happens if you try and replicate the panic stop?
1) ABS software error, which would require energizing the ABS "enable" and "dump" valves inappropriately. Or a sensor error that makes the unit think that the front wheel is locked up when it is in fact rolling and that error persists all the way to a stop, making the ABS dump valve stay open the whole time.
2) There was excess space in front of one or both of the front calipers, so when you squeezed, the brake pads moved in, but the master did not have enough volume to push the brake pads into contact with the rotor. If the brakes worked fine shortly before this failure, than this couldn't be the cause.
I don't see how the dealer's scenario could work. The volume of fluid that is pushed back into the master cylinder when you release the brake is tiny. No way any solids could make it back, especially something large enough to push the master cylinder cup so far from the wall that you would get zero action in a panic stop. I've never seen solids in brake fluid, unless you have never changed it since 2011 or added an incompatible brake fluid.
To have the lever come back to the bar is a lot of fluid displacement. It had to go somewhere.
Only other idea is a crack in the caliper/hardline/ABS body that is opening when the pressure gets high enough.
What happens if you try and replicate the panic stop?
The brakes were serviced by BMW last NovemberCrap, glad your OK. When was the last time the system was flushed?
Another reason for nonworking brakes is inapropriate initial system check. When I drop the bike on right, it bend loosened handguard and press the front brake lever. After that switch on the bike, but brake failure was written on clock, because of not completed initial check. Only in this case I have brake issue. Result was weak and almost fail brakes. After that restart the bike with handguard in correct position. When front brake lever is not pushed until engine start/ ABS initial check all works fine.
Serviced meaning fluid changed and bled or a technician simply validated pads had life left? Hopefully fluid changed.The brakes were serviced by BMW last November
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