ABS 2 problem

[yelostn78]

When I start the bike and roll at 3 mph and the click click happens I get a click POP and then the abs lights blink alternating 1 second intervals- when I hit the abs button the bottom light stays lit- I have tried resetting the ABS and it happens each time- Searched here for about 30 minutes- found mainly issues with resetting and looking for faults-
Here is what I have done so far- I have checked all lines and fluid levels- front brake reads in middle of circle - rear brake is just below max- I re bled each bleed nipple to make sure there was not air in the system. no visible leaks in any of the system- including main abs unit under tank- Battery is charged and electrical system is also reading correctly- I also check the gaps for the wheel sensors- and they are between the min max measurements-

Bike is a 2000 R1150GS w/ absII, 56675 miles

Brake and clutch fluid has been bled 4 times since I bought it brand new in 2000. The brake hoses were replaced about 300 miles ago by me, following the clymer manual instructions to the tee- I have also installed speed bleeders in the front calipers- the rear is traditional as are the two on the abs unit.
new hoses are from touratech- brake fluid is BMW.
Brakes are working as traditional non abs brakes- during ride home(the POP started when first starting the ride home ) the light would do the one second alternating- I would hit the button, the bottom would stay lit- then during the ride at different intervals of time and speed the lights would start the alternating again.


Thanks for any help- let me know if I left anything out.
Yelostn78

[bmwmick]

The "click-POP" is a good description of a failed Hydro Unit. There are two pistons under lots of spring tension in the ABS unit. During the self-test initialization, both pistons are activated and the speed with which they move is measured. It sounds like one of your pistons is not moving correctly. There are two electro-clutches (one for each piston) and one of them is probably failing.

[yelostn78]

Thanks for the reply- I was thinking the same about the failed unit.

I rechecked everything today- after being away from the bike I made a checklist of most of what was discussed here by all. I then began testing all the theories(except the battery on the oscilloscope) and again could not find anything wrong- I traced wiring, everything, so I decided to bleed the abs again, reset the unit and test, ride repeat.
I bought one of the BIG bottles of dot 4 and got to work- the front bled quickly and no air was showing up- I have speed bleeders and using a t fitting in the hose I connected both up- and began bleeding- no noticeable air bubbles. I repeated on the abs(doing one port at a time though) and again no air.
Switched to the rear and bled the caliper- then the abs- wa la- some air bubbles- but I bled for many pumps until I got it- I pumped and filled and pumped and filled and finally some bubbles came out. I then cleaned up and put everything back together.

Fired up the bike and pulled out of the driveway- the click POP was still there but more of a click pop. the good thing was that no fault lights-
So I rode around turning the bike off, at complete stop- restarting and then riding and click pop. so I returned to the garage(my neighbors must I think I am nuts riding around killing the bike and restarting and then smiling sometimes laughing.

So rebled the rear system only this time again- again a lot of fluid for a longer period of time- one more air bubble came out and a few small. sealed everything up and put it back together- this time started the bike and pulled out of the driveway and click click- THANK GOD! the visions of new abs control unit quickly disappeared from my head-


Then The neighbor hit me with her car-


Just kidding,

but rode around again testing and click click each time
so Thanks all for the help- things look good now.
Yelostn78