Brakes Locking Up

[Geezer1000]

Me an the mrs went on a weekend away on our 2004 1200GS this weekend. All was going well until the front and rear brakes locked as I was turning onto a minor road and highsided us off the bike. No injuries to us but the brake servo isnt working anymore. I had to loosen the brake caliper bleed nipples to release the pressure and this got me (slowly) home. Has anyone had any experience of this scary failure?

 

[Number 6]

. Has anyone had any experience of this scary failure?

No, but I'm glad that I removed the servo system from my bike before it went wrong. Glad you're OK

 

[karnevil]

Oh shit!
That sounds like the servo pump thingy.
I had a similar thing,but the brakes didn't stay locked.
First there was no response to the brake lever then the lever rock solid and the brakes full on.Fortunately reset with ignition being turned off but still resulted in around a £12/1300 bill for BMW I believe.

 

[Myke Rocks]

sounds much more like:

.....

 

[Myke Rocks]

sounds much more like:

Sounds much more like the breake lever is trapped on the handguard & keeping the brakes on ever so slightly.
Once you have this condition, the heat from the brake pads expands the fluid, and the brake locks on.
Check this as a first mode.
Myke

 

[Geezer1000]

Sounds much more like the breake lever is trapped on the handguard & keeping the brakes on ever so slightly.
Once you have this condition, the heat from the brake pads expands the fluid, and the brake locks on.
Check this as a first mode.
Myke

Ill have a look at that later. I know that the handguard mod was done on it though. Is there a cure for this do you know?

 

[socket086]

it also happened to me the servo went into a lock up when i was useing the rear brake. i removed the servo and re piped the brake lines. over on adv rider there was a guide to sort the wireing out, although i did not go this way i simply took off the clocks and replaced with sat nav.

 

[Geezer1000]

I probably would have been using the rear brake at the time actually. I moved the handguard cos it had slipped down and was pushing on the front brake. i was hopin thats all it was.

 

[fatbaldbob]

I had this problem on a servo 1150GSA, same thing the front brake would apply itself for no apparent reason and it could happen at any speed, luckily I never binned it though, BMW claimed they had never heard of this happening but it was known on K series bikes. Yet they chose to stop putting servos on I believe after 2004.

There are some threads on the 1150 forum ref this, one theory I was given was if the pads are rubbing slightly the heat gets transfered to the fluid and it expands applying the brake, so it may be worth checking your pistons are fully retracting in the calipers.

Glad your ok, but like many others I too think it has something to do with the servo as it only seems to happen on servo equipped bikes?