BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

Oh the joy. Get your thinking caps on for this one. Here's my story.
Original servo was pronounced dead. Broken electrical pin so the only way it would come to life would be if I pushed down on the electrical harness (plug) when I turned the key. Even then only the front brake circuit would work properly and nothing out of the rear. No brake light on front or rear. Yesterday I put another servo on and this is now my reality:
Servo whines all the time whether the brakes are applied or not.
Front brakes work properly and you can here the servo work harder when applying more brake force.
With the funnel still attached I could get bubbles to rise by applying the brakes.
Rear brakes still dead and I cannot flush new fluid through the secondary circuit as you normally can with the use of the "funnel".
I was getting the alternating 4 Hz flashing signal but then I took the funnel off the rear circuit and fed fluid in manually and that signal went away.
Brake light works with front and rear.
4 Hz flashing light on ABS light only.
Any ideas would be greatly appreciated.
I'm going to go out there again and poke around.
Again...........

I don't know much about the servo, whether it's powered by a switch or an internal relay.

Does the servo engage due to hydraulic pressure or from the brake switches?

Find out why your servo is constantly engaging and work from there.

I wish I had a better answer, but my brakes have been working fine from day 1 (not meaning to rub it in, sorry). Find the common variable and work from there.

You might consider a call to the company referenced in the following ADV topic:

http://www.advrider.com/forums/showthread.php?t=792722

A couple hundred bucks is still less than a replacement iABS modulator, either new or used part.

Thanks for the heads up.
Now that I have 2 of them!

Can't seem to solve the mysteries re:ABS flashing lights on my 02 BMW R1150R. Front brakes work perfectly but rear brakes have no servo actuation....except on rare occasions. Riding the bike "as is" is ok with me and if the warning lights weren't flashing....constantly, I wouldn't notice weak rear brakes. Don't use them much. My greatest concern is that right in the middle of a tight corner -Dragons Tail at Deals Gap- the front brakes may decide to start functioning like the rear brakes. Can't reasonably expect to sell it as is even though it only has <30K miles. From looking at used parts prices on ebay it is more valuable parting it out. Question-what would be a reasonable price to pay my local BMW dealer to remove the ABS and convert to conventional braking. Love the bike otherwise.