07 BMW R1200RT WITH STICKING BRAKE LEVER

[DenverWayne]

I also have a R1200rt with a sticky front brake lever, the bakes work but does not release automatically. I can push the handle forward and the brakes work.(release)

I have disassembled the brake calipers and cleaned the area with brake fluid particular attention to the pads sliding pin it was corroded. I took fine sand paper and cleaned the rod and put a liglht coat of brake grease on the pin. After reassemble no change. The brake fluid is about 16 months old. The levels are correct. The rear brake works normally.

 

Would flushing be of any help, any suggestion for diagnosing ?

[dirtrider]

17 minutes ago, DenverWayne said:

I also have a R1200rt with a sticky front brake lever, the bakes work but does not release automatically. I can push the handle forward and the brakes work.(release)

I have disassembled the brake calipers and cleaned the area with brake fluid particular attention to the pads sliding pin it was corroded. I took fine sand paper and cleaned the rod and put a liglht coat of brake grease on the pin. After reassemble no change. The brake fluid is about 16 months old. The levels are correct. The rear brake works normally.

 

Would flushing be of any help, any suggestion for diagnosing ?

 

Evening  DenverWayne

 

It really sounds more like either a sticking lever at it's pivot pin, or the master cylinder piston is sticking in it's  bore  at top of travel.

 

About all you can do to diagnose either of those is to dig in, partially disassemble & find out 'what' is actually hanging up.

 

A flush wouldn't hurt but I seriously doubt it would help your immediate problem.

[DenverWayne]

Thanks for the information. I flushed the front brakes, that seemed to be of some help, the brakes release some of the time. I am suspecting the master cylinder at this point, the brakes release but the lever does not move very much. I think that suggests  the master cylinder piston is suspect. As luck has it I am 1100 miles from home. I plan to leave Port Aransas Texas in about a month and return to Denver. I am thinking that another flush might help. The nearest Dealer is 180 miles away in San Antonio. It can wait.

 

I will keep you posted.  Thanks for your help.

[DenverWayne]

Thanks for the information. I flushed the front brakes, that seemed to be of some help, the brakes release partially some of the time. I am suspecting the master cylinder at this point, the brakes release but the lever does not move very much  As luck has it I am 1100 miles from home. I plan to leave Port Aransas in about a month and return to Denver. .

 

 

In checking the master cylinder I noticed the left side of the master cylinder has a bleed valve located just below the check brake fluid window. I have not bled that valve. Does it bleed the piston?  Andy special technique to bleed this valve?   I am suspicious the piston is sticking, I wpould like  to bleed the valve but don"t want create a problem.   Thanks  Wayne

[Skywagon]

DenverWayne….I live in Houston, have a beach house in Port Aransas, and will probably be down in the next 2 weeks or so.  If you are lacking tools or if you want to get a part let me know and I may be able to bring it to you.  If you need to order a part the local dealer near me is Mancuso.

[dirtrider]

11 hours ago, DenverWayne said:

In checking the master cylinder I noticed the left side of the master cylinder has a bleed valve located just below the check brake fluid window. I have not bled that valve. Does it bleed the piston?  Andy special technique to bleed this valve?   I am suspicious the piston is sticking, I wpould like  to bleed the valve but don"t want create a problem.   Thanks  Wayne

 

Morning DenverWayne

 

That upper bleed nipple is more for initial upper system bleeding (basically pre-bleeding) as it purges the air from the upper line & master cylinder area.  That upper bleed nipple is basically used when a completely dry master cylinder is installed to purge the master cylinder & vertical brake line so that all the air in that area doesn't need to get forced through the remainder of the braking system.

 

Once the system is together & used for a while then any air in the upper part of the system will automatically work it's way back 'up' the line & into the master cylinder bore where it will then automatically work it's way 'up' through the take-up port & into the master cylinder reservoir.

 

If you want to bleed  that nipple then it won't hurt anything but if you now have decent brake lever pressure vs braking pressure then it won't help anything either

[DenverWayne]

Thanks, Dirtrider for your expertise on the master cylinder, I will leave it alone. The brakes stick, just not as bad. I intend to leave it alone until my return yo Denver.

 

Thanks to Skyrider for his offer. I will not need parts for now. thanks for the offer.

 

Happy trails to you.

[DenverWayne]

Follow up on repairs to sticking brake lever, upon disassembly the lever bearing was damaged and springs were worn, the springs  were replaced due to age, 12 years old. Parts had to be ordered from Germany (two weeks wait) all is well the brakes are back to normal.

 

Thanks for your help.  Happy trails to you.

 

Denver  Wayne