ABS brake bleed test
All, I would like to get your thoughts on this. I have a 2004 1150RT with servo brakes. While doing a brake bleed, I made the mistake of letting the rear master cylinder get too low on brake fluid. When I removed the black rubber insert in the MC I could hear air being sucked into the brake line. I did a rebleed of the rear. I have a GS911, so when I do the ABS brake bleed test, the rear will not pass the test. It reports that the minimum pressure has not been met. I have test rode the bike and the rear brakes will stop the bike very effectively and the ABS seems to be functioning normally. The GS 911 reports no faults. The front brakes have passed the bleed test. If there is air in the rear brake lines, with the servo system, is it even possible to manually rid the rear system of air or is a trip to the dealer necessary? Also, since there is a vent tube coming from the ABS unit is it possibe that the air trapped in the line could/ would be exhausted out? I believe I have most of the air out. I have done this service before without the benefit of the GS911 and have no idea if the brakes would have passed the pressure test. Thanks for your help. Mike
The first time I did an "unassisted" bleed, it seemed to work, too...
A couple of days later, up on the freeway at 60 MPH, I grabbed the front brake lever and it came all the way back.
I recommend a full and proper flush of all circuits, and get it pressure-tested too.
GS-911 has a support forum within Google Groups. There has been some discussion there. I'm not positive but not-passing is not uncommon. My 2004 RT seems to pass the GS-911 test but only by a small margin.
Couldn't find any info there. In any case the rear brakes will pass the test now. Not sure what changed. I was going to rebleed them for a third time, but checked the internal pressure again before I did that. I think with the servo being vented that may have something to do with it.