2009 R1200 RT Rear Brake Issue

[Bigfish]

Rear brake was rock hard and brake failure light on.

GS911 procedures did not help.

Performed Rear Brake bleed manually then proceeded with the ABS assisted rear bleed. 3 time.

 

No error codes found. Rode bike and rear brake feels hard with hardly any movement... then got the Brake failure warning on dash again.

 

GS911 Code after this last try was: 

2 fault codes found:

 24105  Rear pressure sensor, control circuit, invalid signal (The fault is not present now.)

23980  Pressure Sensor, rear wheel circuit : Signal implausible (pressure monitoring) The fault is not present now.

 

What might have led up to this issue:

On a late night ride home from work with no traffic, I decided it would be a good opportunity to practice some emergency braking stops and try and activate the anti lock braking.

everything went well but when I  got on the bike a week later, I noticed my rear brake was rock hard but luckily the front brake was still working.

 

I did a GS911 brake bleed sequence ( both front and rear) and it seemed to fix the issue for a month.

 

Bike sat another 2 weeks then went to ride and same rear brake issue. But this time I've done the GS911 rear only brake procedure 2 complete times and it is not working.

 

Not sure if I need to do the front brakes as well as the rear. That is the only difference from when I got it working the first time. Since the front brakes seem to be fine I just did the GS911 rear only.

 

Any help would be appreciated. Nice weather on the horizon and I gotta have a safe bike to ride.

 

Thanks!

[dirtrider]

23 minutes ago, Bigfish said:

Rear brake was rock hard and brake failure light on.

GS911 procedures did not help.

Performed Rear Brake bleed manually then proceeded with the ABS assisted rear bleed. 3 time.

 

No error codes found. Rode bike and rear brake feels hard with hardly any movement... then got the Brake failure warning on dash again.

 

GS911 Code after this last try was: 

2 fault codes found:

 24105  Rear pressure sensor, control circuit, invalid signal (The fault is not present now.)

23980  Pressure Sensor, rear wheel circuit : Signal implausible (pressure monitoring) The fault is not present now.

 

What might have led up to this issue:

On a late night ride home from work with no traffic, I decided it would be a good opportunity to practice some emergency braking stops and try and activate the anti lock braking.

everything went well but when I  got on the bike a week later, I noticed my rear brake was rock hard but luckily the front brake was still working.

 

I did a GS911 brake bleed sequence ( both front and rear) and it seemed to fix the issue for a month.

 

Bike sat another 2 weeks then went to ride and same rear brake issue. But this time I've done the GS911 rear only brake procedure 2 complete times and it is not working.

 

Not sure if I need to do the front brakes as well as the rear. That is the only difference from when I got it working the first time. Since the front brakes seem to be fine I just did the GS911 rear only.

 

Any help would be appreciated. Nice weather on the horizon and I gotta have a safe bike to ride.

 

Thanks!

Afternoon  Bigfish

 

If your 1200 was a 2005 or 2006  (with I-ABS) then I would be pretty evident but with you having a 2009 with I-ABS gen2 then I'm not sure what you are dealing with. 

 

The usual rear brake failure on the 2009 (I-ABS gen2) is a rear servo motor brush issue but that doesn't give you a rock hard rear brake pedal feel & almost always gives you a servo motor failure fault on the GS-911. 

 

With the GS-911 fault codes you did get & the apparent non functioning rear brake pedal a guess on my part is a sticking valve inside the ABS  module. Probably the valve that controls the switching between the servo pump controlled rear braking & rear brake-pedal master cylinder rear braking. 

 

My best suggestion is to call Module Master   (208) 892-0764   & see if they have an idea on what is going on as they repair these things daily. 

 

A quick test you can do is to put the motorcycle on the center stand, then turn the key ON (do not start engine), then while spinning the rear wheel with your foot (or a helper) try pulling the front brake lever.  (see if that locks the rear brake up) if so then follow that up with same key-on but see if you can stop the rear wheel with the rear foot pedal.  This might tell us something about the problem depending on what happens & when. 

[Bigfish]

DR,

Thanks for helping me with this.

I did as you suggested with Key on but not started.

 

Front Brake Lever stopped the rear tire just fine.

 

Rear Brake also stopped the rear tire just fine but rear brake feels weird.

 

Including pics. 

 

The rear brake pedal seems off. look at pics closely. I think whatever the piece is in the aft side of lever is locked up. Brake just feels hard and doen't have that nice smooth mushy feel like it should.

 

Looks like the whole rear brake is out of alignment. Bike was not dropped. Did I put too much force when practicing emergency braking?

 

Maybe the part that seems locked up is causing this misalignment?

 

 

 

[dirtrider]

15 hours ago, Bigfish said:

DR,

Thanks for helping me with this.

I did as you suggested with Key on but not started.

 

Front Brake Lever stopped the rear tire just fine.

 

Rear Brake also stopped the rear tire just fine but rear brake feels weird.

 

Including pics. 

 

The rear brake pedal seems off. look at pics closely. I think whatever the piece is in the aft side of lever is locked up. Brake just feels hard and doen't have that nice smooth mushy feel like it should.

 

Looks like the whole rear brake is out of alignment. Bike was not dropped. Did I put too much force when practicing emergency braking?

 

Maybe the part that seems locked up is causing this misalignment?

 

Morning  Bigfish

 

There is definitely something wrong with that rear brake pedal. It does look bent, or possibly bent,  loose,  or broken at it's attachment pivot.

 

I can't see enough of the pedal at it's pivot attachment area to see what is going on in that area. 

 

In any case you need to address that brake pedal as per the (key-on) test your ABS servo pump is working. 

[SD1]

Having just reassembled these brake components, yes the lever is bent, the stopper bolt should strike the detente right in the middle. The black rod is the push rod for the rear brake master cylinder, possibly a failed rear master cylinder?  When I bled the rear brake a few days ago, it moved freely and easily through its stroke.

 

.

[Bigfish]

Follow up to this posting. Master BMW mechanic got the same results when bleeding rear brake and same codes. He dove deeper into the codes and looked up Module Masters and unfortunately the code we are getting is something that is not repairable by them.

Biting the bullet and paying for a very expensive new unit. I need to know that my brakes are safe especially knowing my wife rides as pillion quite often. No more justification of cost needed.

 

Thanks for trying to help.... very much appreciated.

[beemer chuck]

Looks like you need part 34 51 7 715 109. Seems to be used on all R1200 from 07 thru 12.and some k1200-1300.

many of them on EBay for $300 and up.