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rear brake dragging

swift

New member
I have a 2005 R1150 RT with 90K on the bike with Integral ABS system I have had the bike since 2014 with very little problems with the brakes. In 2015 I replaced the rear brakes pads that's when the problems started. After I replaced the brakes pads the brakes started dragging and the disk started to turn a darker colour than the front I pulled the caliper off and found the square piston seals had rolled a round in the bore grove so I replaced them, I still have the same problem, borrowed a spare caliper and still the same problem. I replaced the brake lines with Spiegler Brake lines it helped the problem a little bit the disk was very hot to touch before now its very warm about twice as warm as the fronts. I have replaced all the brake fluid, first when I got the bike and then when I changed the brake caliper piston seals and when I changed out the brake lines each time I followed the manual very closely. I don't notice any different in the brake operation the self diagnosis test all work. is there a chance that I over filled the ABS modulator or is there another problem that I am missing or not doing.
 
Did you adjust the pedal pushrod? Does it allow the rear master cylinder piston to fully retract?
 
A misadjusted brake pedal may be the issue. I made the mistake of adjusting the rear brake pedal, caused the distruction of the caliper and rotor. Make sure the rod going off the pedal has play in it when it is in the unactivated position . You don't want any pressue against the rear M/C until the pedal is depressed.

Another issue I have had when replacing brake pads is too much fluid in system causing brake drag. When one push the pistons back in because the pads are thicker, remember they were filled with more fluid due to thin pads. I have had to open bleeders when compressing pistons and then refill after pads were seated.
 
A misadjusted brake pedal may be the issue. I made the mistake of adjusting the rear brake pedal, caused the distruction of the caliper and rotor. Make sure the rod going off the pedal has play in it when it is in the unactivated position . You don't want any pressue against the rear M/C until the pedal is depressed.

Another issue I have had when replacing brake pads is too much fluid in system causing brake drag. When one push the pistons back in because the pads are thicker, remember they were filled with more fluid due to thin pads. I have had to open bleeders when compressing pistons and then refill after pads were seated.

On integral ABS the control system (master) is separate from the power (caliper)
If fluid was held back then the rear servo motor would be running and you would get an ABS fault
 
I have a 2005 R1150 RT with 90K on the bike with Integral ABS system I have had the bike since 2014 with very little problems with the brakes. In 2015 I replaced the rear brakes pads that's when the problems started. After I replaced the brakes pads the brakes started dragging and the disk started to turn a darker colour than the front I pulled the caliper off and found the square piston seals had rolled a round in the bore grove so I replaced them, I still have the same problem, borrowed a spare caliper and still the same problem. I replaced the brake lines with Spiegler Brake lines it helped the problem a little bit the disk was very hot to touch before now its very warm about twice as warm as the fronts. I have replaced all the brake fluid, first when I got the bike and then when I changed the brake caliper piston seals and when I changed out the brake lines each time I followed the manual very closely. I don't notice any different in the brake operation the self diagnosis test all work. is there a chance that I over filled the ABS modulator or is there another problem that I am missing or not doing.

Did you use the correct pads as per Max fiche?
BMW is very specific as to the right compound on integral ABS bikes. I am not 100% sure why.
Friction coefficient could be a factor

If you overfilled the modulator it would drain out the overflow hose - maybe check that it is not pinched or clogged.
 
Rear brake Dragging

Thanks for your inputs. I did not mention it but I did check to make sure the rod from the brake pedal to cylinder was not putting pressure on the system.
The disk runs hot after I have ridden the bike. At start up the ABS goes through it's check and the ABS Warning Light goes out, and both lights are out after I have pull out and remain that way the entire trip but at each stop I find the disk very hot to touch. I will be putting the bike on a lift and will be doing service work on it and I will go over the rear caliper to see if the caliper body shafts are tight and that the pads are not misaligned. I will also check the difference from the factory to EBC brake pads.
 
I had the same problem after installing the EBC pads. When I took the caliper off to investigate I found a thick layer of paint on the edge of the metal plate the pads are fastened to. Kind of like a drip or paint sag. Just a little filing of that paint "glob" allowed the pads to move freely in the caliper and my problem was solved! An easy fix, maybe you will be this lucky too.
 
For what its worth......

My bike has the integral setup and I rarely use the rear brake pedal. Still, after coming to a stop at home, the rear disc is significantly warmer than the front. Sintered brake pads are called for on my '03 R1100S however I've been running SBS organic pads for years after I noticed the rear disc was starting to get chewed up (grooved). Its smooth as a baby's bum now. I put the higher temperature of the disc down to there being only one disc versus two on the front plus the fact that its a smaller disc than the fronts. If your rear wheel spins freely on the centre stand immediately after stopping, I'm going to venture a wild assed guess and say you may not have an issue. :dunno

At the same time, you've probably checked that all the sliding pins in the caliper are properly lubed and operating operating as they should otherwise you might not be getting full release of the rear brake. A consultation with an expert is recommended.
 
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