locked front wheel

Riceburner

Riceburner

Well-known member
Stopped to help out a rider yesterday. He was in the middle lane on Elgin Mills. His front wheel was locked up. Seems he rode about 60km and then his front brakes locked up. After about 20min the brakes went back to normal and we pushed the bike to the parking lot. BMW R1200R with braided lines. So I'm thinking it's water in the brake fluid. When it heated up enough the water caused enough expansion to lock the brakes....and then once cooled down it was fine again. Any other opinions?
 
Typically, water in the lines exposed to heat boils, and you *lose* brakes, not the other way around. There's quite a bit of expansion in the master cylinder. I've never heard of what you propose...

Did it have ABS? Sounds like some other sort of failure.
 
Riceburner said:
Stopped to help out a rider yesterday. He was in the middle lane on Elgin Mills. His front wheel was locked up. Seems he rode about 60km and then his front brakes locked up. After about 20min the brakes went back to normal and we pushed the bike to the parking lot. BMW R1200R with braided lines. So I'm thinking it's water in the brake fluid. When it heated up enough the water caused enough expansion to lock the brakes....and then once cooled down it was fine again. Any other opinions?
Click to expand...

Anti-lock brakes? How much meat was left on the pads?
 
If it had aftermarket brake lever, it's possible that the lever was not allowing fluid to escape out of the master cylinder into the reservoir when the brake lever was released. (Seen it before)
 
Brian P said:
If it had aftermarket brake lever, it's possible that the lever was not allowing fluid to escape out of the master cylinder into the reservoir when the brake lever was released. (Seen it before)
Click to expand...
I like this one! Big issue with the cheap ones that don't vent properly.
 
Brian P said:
If it had aftermarket brake lever, it's possible that the lever was not allowing fluid to escape out of the master cylinder into the reservoir when the brake lever was released. (Seen it before)
Click to expand...

+1 Heard this happening alot with the ebay shorty levers.
 
It did have ABS. I thought ABS failure just turned off the ABS part, not lock it. Don't know if the levers were aftermarket or not. I did pull them away from the bar, but didn't check the plunger it pushed on. Either way the guy said it was still under warranty and would take it in. Wonder if it's BMW full warranty or not :snorting: ....see other thread about GPbikes warranty.
 
It's a German vehicle. The warranty is voided by operating the vehicle. All problems are the customer's fault.

:)
 
A friend once mentioned BMW suggest yearly brake flush on some of their bikes. Maybe to do with that.
 
If it's the system with the servo pump, maybe it........no, can't see how the ABS system would apply pressure to the front pads. Rears yes, but not fronts. Not to worry if he has warranty they will fix it. Might argue a bit, but they are proud of their bikes.
 
I find it hard to believe that any Bimmer rider would put cheap aftermarket china levers on their bike. So its likely not this.

Its not the ABS either, it wouldn't cause the wheel to lock up.

I'm pretty sure the new Bimmers don't have servo brakes, so not this either.

The bike comes with 3 year unlimited km warranty, and free roadside pick up which would bring the bike back to the dealer. If I were him. I'd have refused to continue riding it for safety's sake and have the tow company pick up the bike. I have absolutely no doubt, unless he tampered with this brakes prior and messed something up, that BMW would pick up the tab for any repairs.

.
 
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