Rear brake problem

[Grrooney]

Hello, I am new to the forum. I have had an 03 R1150R now for 2 years with 13000 miles - great bike. Twice recently when using rear brake on steep hills, ABS warning starts flashing, and rear servo quits working. Both times the problem has corrected itself when the bike is switched off and on again. There is no apparent problem with front brake. I would like to know if I do a complete brake fluid flush, is it likely to cure the problem, or do you think that the rear brake servo is on the way out. I have no record of a brake fluid flush having been done in the last 6 years. Thanks.

[Buckster]

Welcome.....the brakes should be bled annually! I do the clutch every year with the same dot-4 brake fluid as well. I don't have ABS so I cannot comment on that part of it. I would start with the fluid flush first and go from there.

[Grrooney]

Thanks. I will replace the fluid and see what happens.

[hank]

Take the fuel tank off and check the fluid levels in the ABS unit, I had this problem when the fluid was low. The servo ABS bikes have two hydraulic circuits each for front and rear brakes. One circuit goes from the brake pedal to the servo unit and the other goes from the servo to the rear brake. Same at the front, handle bar to servo, servo to brakes.

[Grrooney]

Thanks Hank. I will let you know how I get on.

[Grrooney]

Took tank off and checked fluid levels today. Both levels are ok. I suppose the next step is to flush the fluid out. That will have to wait a while. I noticed the fluid in rear circuit is a darker colour than front circuit. Maybe it has never been changed. The job will have to wait a few weeks as I need the bike.

[Dr. Strangelove]

If you're close to a dealer a computer check on the diagnostic plug would be useful.

That is the exact symptom I had on my Stella! and the rear servo was gone (and I don't know what to do with her ). When you restart the bike all is ok until you hit the brakes then the flashing commences.

Need to rule that out, as that could be a fatal illness. Well not fatal, but $2700, or removing the abs and going without. Or it could be a sensor, or any other thing.

There is a place called modulemasters.com in Moscow, ID that rebuilds SOME of the units, not mine unfortunately yet.

Good luck and realize that you have no abs at all.
John

[MajorElint]

I started having this same problem after I had my rear rotor and pads replaced. The dealer basically told me the unit is shot.

I havn't bothered to get it fixed mainly because he quoted me $4,000 in parts and labor, which is almost what I paid for the bike.

But I did have a friend who was a bmw tech tell me that you could change the depth on the sensor and that may help. Also changing the fluid and then taking it to an empty lot an just mashing on it can sometimes help as well. From what I was told.

[opposedtwin]

Welcome, and welcome to arguably the most discussed topic on the forum:flashing abs warning lights and no rear brakes. Not sure which year BMW solved this issue with the R1150R (did they solve it?) but I know it began with the 2002 which is what I have. Have owned in excess of 20 BMW's; all their many versions beginning in 1976 with my R75/6 and have experienced some problems; especially with the first K100RS. I'm thankful my first BMW wasn't my present R1150R because likely I would have owned only one and missed out on all the fabulous rides I have been fortunate to experience on BMW's. Now to address your issue you only have to do a search on brakes or contact sweatmark. His solution is best, imo.

[Dr. Strangelove]

"contact Sweatmark,"
the ultimate solution!

I may be going there myself