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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: KCinSB on May 14, 2012, 11:27:48 PM

Title: '93 K1100 Frnt Brake stays engaged until lever flicked Fwd
Post by: KCinSB on May 14, 2012, 11:27:48 PM

This may be something someone else has seen, and I'm looking for any help in figuring it out!  The front brake on this K1100RS works fine to stop, but then does not release all the way until I flick the lever forward. It's been that way for awhile now, and in fact I've begun to use the feature when stopped on an incline.............   Bad habit I know   :loco:   Sometimes I forget to flick though, and then I feel the bike decellerate quick with power off!!
Anyhow, has anyone seen this before?  What might be the trouble?  Without any ideas, I will just go through the front master cylinder and look things over I guess.  Recently did a pressure flush on the system with Dot 4, from top to ABS, to wheels, but the problem did not change.

Title: Re: '93 K1100 Frnt Brake stays engaged until lever flicked Fwd
Post by: CRASH on May 15, 2012, 01:38:54 AM

Sticky brake lever or sticky master cylinder.  I would bet the master cylinder is corroded and sticking.

Title: Re: '93 K1100 Frnt Brake stays engaged until lever flicked Fwd
Post by: Inge K. on May 15, 2012, 05:29:12 AM

The pivot bolt moves inside a stationary bushing, I`ll guess a corroded pivot bolt is the reason to the problem.
When undoing the pivot bolt, the bushing follows with.

Inge K.

Title: Re: '93 K1100 Frnt Brake stays engaged until lever flicked Fwd
Post by: KCinSB on May 15, 2012, 11:26:22 AM

Looks like I will have to commit to dis-assembly and related mess!  I had heard that there is a small port in the master cyl that can cause this, but not sure where to see that.  I'm not afraid to take it apart, just hoping to know as much as possible before.  I think it would be wise to have a rebuild kit on hand also.   KC

Title: Re: '93 K1100 Frnt Brake stays engaged until lever flicked Fwd
Post by: BobZ(IL) on May 16, 2012, 09:50:02 PM

May need to replace the brakes lines. That fixed mine.

Title: Re: '93 K1100 Frnt Brake stays engaged until lever flicked Fwd
Post by: mystic red on May 17, 2012, 07:58:25 PM

I cured mine by disassembling brake lever and cleaning it well. Then I lubed it and it went back to sticking. Cleaned and left dry and no more problems. YRMV.

Title: Re: '93 K1100 Frnt Brake stays engaged until lever flicked Fwd
Post by: KCinSB on June 12, 2012, 12:42:25 AM

Just to close the loop..........   It was the pivot bolt and "teflon" bush, just like Inge K said.  Simple fix, take the bolt out the bottom, no fluid loss issues, clean accumulated road crud out of every where, clean the bolt and bush, dry lube, replace bolt, works fine.
Now I kinda miss my "hill holder"...............      :loopy:     just kidding..........