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#1011109 - 05/11/18 02:20 PM Re: Issue Bleeding Brakes [Re: MichiganBob]  
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Originally Posted by MichiganBob
Good Morning, I pulled off both speed bleeders and no fluid is coming out of them. The brake lever only moves about .25 inch. I did notice that there is a bleeder valve on the master cylinder itself. Can this have a role in what is happening? I'm not sure what that valve does?

Thanks.

Bob



Morning Bob

That bleeder on the master cylinder is for pre bleeding the master cylinder (you don't need to mess with that unless you run the master cylinder out of fluid).

That "no fluid coming out" is kind of puzzling -- a person would think that if the system had enough residual pressure to keep the front wheel from turning that you would have had fluid gushing out when you removed the speed bleeders.

Can you now turn the front wheel with the speed bleeders removed?

If you can't turn the front wheel with the speed bleeders removed then try gently prying the front bake pads off the rotors then see if you can turn the wheel (caution: pry only on the metal of the brake pads not the fiber friction surface).

You might also try re-installing the speed bleeders then turning the key on & pumping the brake lever (maybe the ABS system has the accumulator valve shut but even that should have shown fluid run out when you removed the speed bleeders--(puzzling for sure).

Your problem initially sounds/sounded like remaining pressure in the front brake system but the no-fluid coming out when removing the speed bleeders kind of points to a mechanical lock-up (like poor fitting pads, or too thick pads, or something in the caliper/brake pad match up)


D.R. ___
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#1011116 - 05/11/18 02:46 PM Re: Issue Bleeding Brakes [Re: MichiganBob]  
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Thanks DR. I'll try your suggestions. It was weird when I started bleeding the first side that with the speed bleeder open, fluid was coming out fine and then pressure build up and the system locked. I was thinking that maybe the check valve closed on the bleeder but I now have the stock bleeders back in and can't get any fluid to come out of them.. What if I actually removed the calipers from the disks to free the wheel?

Bob

#1011118 - 05/11/18 03:07 PM Re: Issue Bleeding Brakes [Re: MichiganBob]  
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Originally Posted by MichiganBob
Thanks DR. I'll try your suggestions. It was weird when I started bleeding the first side that with the speed bleeder open, fluid was coming out fine and then pressure build up and the system locked. I was thinking that maybe the check valve closed on the bleeder but I now have the stock bleeders back in and can't get any fluid to come out of them.. What if I actually removed the calipers from the disks to free the wheel?

Bob


Morning Bob

You could do that but probably no gain over just prying the pads back off the rotors.


D.R. ___
Sent from my rotory dial wall phone!
#1011130 - 05/11/18 07:33 PM Re: Issue Bleeding Brakes [Re: MichiganBob]  
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Good afternoon. That was dumb. I thought the wheel was off the garage floor enough on the centerstand to move. I lifted it a tad and the wheel turns. So now I'm back to where I started. There is fluid in the reservoir but only slight lever travel. I put the stock bleeders back on. No fluid gushing out. I'll try tonight with the bleeder open and running if you think that it might make a difference I,m thinking of attaching a mighty vac to see if I can such fluid down the brake line. Make sense?

#1011131 - 05/11/18 07:39 PM Re: Issue Bleeding Brakes [Re: MichiganBob]  
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I;m heading out the door and figure I would give the handle one more try and it felt like something unstuck and now I have handle again. I'm thinking of either speed bleeders again and bleed or stock bleeders and mighty vac. Recommendations?

Thanks.

Bob

#1011181 - 05/12/18 08:51 PM Re: Issue Bleeding Brakes [Re: MichiganBob]  
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Good afternoon, brakes are bled, haven't taken for test ride but will when it stops raining. It does seem that the master cylinder piston may occasionally be stuck and then releases. This is intermittent rather than continual. What can be done to remedy that other than a high high ticket replacement of the cylinder? Can it be disassembled and inspected without to much complexity?

Thanks.

Bob

#1011187 - 05/12/18 10:18 PM Re: Issue Bleeding Brakes [Re: MichiganBob]  
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Originally Posted by MichiganBob
Good afternoon, brakes are bled, haven't taken for test ride but will when it stops raining. It does seem that the master cylinder piston may occasionally be stuck and then releases. This is intermittent rather than continual. What can be done to remedy that other than a high high ticket replacement of the cylinder? Can it be disassembled and inspected without to much complexity?

Thanks.

Bob


Afternoon Bob

Darn good question.

I haven't ever been into a 2010-up front master cylinder. The piston might come out easily or might be problem, I just don't know. I don't see any internal parts available for the 2010-up master cylinders (at least from BMW) so I'm not sure what you will encounter trying to take it apart.

If it wasn't hanging up before the latest work & is now free then you might try (carefully) riding the bike as the problem might not be an issue with normal brake usage. Do be very careful until you are sure it will always work.


D.R. ___
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#1011254 - 05/14/18 01:37 PM Re: Issue Bleeding Brakes [Re: MichiganBob]  
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Top Of The Day,

Will test as soon as it stops raining. Flash back to post last Fall when twice I pulled the lever and there was no brakes and quickly pulled again and there they were. We agreed to start with a good brake bleed which I just did. Not sure if that event and the recent one is related in any way. I'll ride in places where I can safely stop with just the rear brake (if necessary). Stay tuned.

#1011365 - 05/16/18 12:02 AM Re: Issue Bleeding Brakes [Re: MichiganBob]  
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Good Evening,

Test ride and brakes worked well. I have a trip down to Lexington first weekend of June (Red Mile Flat Track -- yahoo!!!) so will get in a good test on the 800 mile round trip. Something else though DR that I wanted to pick your brain about. When the bike starts, it's idling at 1600 which seems and feels high. It is almost too fast in first for my crappy dirt road to the pavement. Once warmed, it drops to 1100. Maybe somethings hung up so I will check the throttle bodies. Other than that, I'm thinking that the idle is computer controlled rather than the good old days when there was an idle screw. So does the 1600 and then 1100 seem out of specs for a 2012 1200RT, and if so, what's the fix. Thanks as always.

Bob

#1011396 - 05/16/18 11:53 AM Re: Issue Bleeding Brakes [Re: MichiganBob]  
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dirtrider Offline
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Originally Posted by MichiganBob
Good Evening,

Test ride and brakes worked well. I have a trip down to Lexington first weekend of June (Red Mile Flat Track -- yahoo!!!) so will get in a good test on the 800 mile round trip. Something else though DR that I wanted to pick your brain about. When the bike starts, it's idling at 1600 which seems and feels high. It is almost too fast in first for my crappy dirt road to the pavement. Once warmed, it drops to 1100. Maybe somethings hung up so I will check the throttle bodies. Other than that, I'm thinking that the idle is computer controlled rather than the good old days when there was an idle screw. So does the 1600 and then 1100 seem out of specs for a 2012 1200RT, and if so, what's the fix. Thanks as always.

Bob


Morning Bob


BMW doesn't furnish a specific cold fast idle spec as it is computer controlled (using stepper motors) & is dependent on many things, like ambient temperature & oil temperature, battery voltage after start-up, & emission performance programming.

They do tend to idle a little high after cold start as that assures that the alternator starts charging right away, it also helps to quickly heat the catalytic converter so it starts working quicker (part of the new emission regulations), but it shouldn't fast idle fast for long.

As for the hot curb idle, it is also computer controlled using the stepper motors based on engine temperature, battery voltage, engine load, stored adaptives, o2 sensor input, etc.

Not much you can do with either fast idle or curb idle as neither are adjustable.


D.R. ___
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