K11 Owners Group

[planthead]

Hope someone can help with this.

One of my rear brake pads is wore down to nothing and the other looks basically untouched. Anyone know what might be causing this?

Thanks,
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'93 K1100LT 61k

[Jim]

time to rebuild the caliper? Seems like maybe it's stuck. How often do you change your brake fluid? Should be done once a year. It would help if you'd put the year and model of your bike in your signature. Might be good to know the current mileage, also...
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Jim
1997 K1100LTSE 94,000 - still has gremlins!
1995 R100RT Classic 16,650 crashed - repaired!
1992 K75RTP 46,000

"We shall not all die, but we shall all be changed."

[Flying Duck]

[Allen Nelson]

You should pull off your rear caliper and check to see if the pistons are moving smoothly or are they hanging up. Lots and lots of motorcycle owners (and shops too) don't clean the calipers with any kind of regularity....which can lead to poor operation. Some times just cleaning them up will do the trick....but if that doesn't work....and like what was already suggested....time to rebuild or replace....depending on what you find inside after opening them up and cleaning the bores.

The other advice is especially good if you plan on keeping the bike....changing brake and fork fluid are good ideas to keep things working efficiently over a longer period of time....

P.S.
and don't forget coolant too....
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REDBRICK, '96RS (formerly owned), K11OG#5
2011 Triumph Sprint GT
Not a turncoat...and do miss my special K

[planthead]

[Allen Nelson]

I don't know that I would go to that extreme first (I've always subscribed to dealing with the simplist potential solutions and eliminating them first).....just pull the caliper from the wheel (don't disconnect brake line), spray it down good with brake cleaner and wipe it as clean as possible (do not pull back dust covers). Then I would push on the pistons to see how smoothly they are sliding (keep in mind anything you do when pushing back the pistons will result in fluid backing up to the master.....so you may want to adjust master fluid level). If nothing is hanging up at this point, you may be in the clear.....some times debris in the fluid will block the pressure to a piston(common occurance if the bike has sat allot during it's earlier life), which can result in the uneven wear. So if the pistons are moving well, I would proceed with replacing the fluid, bleed the system well and probably pop in a new set of pads....then check the pads periodically for uneven wear.

Chances are though there is a problem with the pistons of the pad with less wear. One thing to keep in mind (it's been a while since I've thought about the foibles of owning a K11) the rear pads on a K11 don't wear nearly as fast as the front....and depending on any records (if they exist) you may have from PO, the last time those pads were changed could tell you a lot. I for one hardly ever used the rear brakes. I know on mine I only changed them once in 10 years and even then they still had lots of meat left on them...I wanted to take a look at the insides to see if any pitting or other abnormaility was developing
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REDBRICK, '96RS (formerly owned), K11OG#5
2011 Triumph Sprint GT
Not a turncoat...and do miss my special K

[Flying Duck]

When you're pushing the pistons out and then applying the brake to see if they're moving smoothly put a piece of plywood or something between the pads. That'll make it easier to get them back apart. Or you could get really fancy and buy a tool that separates brake pads.
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93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

[planthead]

I cleaned the caliper out and put it back together.

What does correct brake opperation look like? When you depress the brake peddel should you see significant movement inward toward the rotor and movement away at release? Mine does short pulses. And when I reset both pistons and then pumped the brake peddel only one side would move at first, the other side would not move until multiple pumps.

It would also appear that the one pad is not fully retracting from the rotor. When I spin the wheel I here a slight rasp and it does not rotate as freely as I would expect. I imagine it was doing this the whole time the one side was wearing and I just hadn't noticed.

I have not bled the system yet; I did not have any fluid on hand (thought I had a bottle) when I was looking at this. Hoping to have some time this evening or the next to look at it again.
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'93 K1100LT 61k

[Allen Nelson]

Sorry to hear that....but it pretty much cinches it.....your going to need the calipers either rebuilt or replaced. Without opening them up you don't know what's causing it....but your description leaves little doubt

If you're not up to perfomring the analysis or repair, I would get it into a reputable shop. BTW.....not all BMW shops are reputable....especially when it comes to K11's....so you may want to do a seperate post here to reach out to other owners and find out which shop in your area (if there are other K11 owners in your neck of the woods) has the best reputation.

Seeing as your dealing only with a brake issue, an independant motorycycle mechanic with a good reputation may be an alternative.....the only issue that might pop it's ugly head is the bleeding of the ABS system....which can be difficult. It's hard to make a difinitive analysis here....but if you can give more information it would help all of us give you better feedback on the potential issues. For instance, do you know the previous owner(s)......do you have any records of the maintenance of the bike.....and if you do check the records (dates and mileage) of brake service (fluid changes)....did the bike sit for long periods of time.......what ever kind of information you can give us will help. But with little doubt, your looking at having the brakes worked on.

Again, you don't know what's causing it at this point (gummy old brake fluid, debris in the system, marred, warped or pitted sleeves/pistons)......post any information your able to tell us though about the bikes history....year?.....mileage?...gerenal condition?......what records you do have?
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REDBRICK, '96RS (formerly owned), K11OG#5
2011 Triumph Sprint GT
Not a turncoat...and do miss my special K

[planthead]

[Allen Nelson]

Sounds like your on track and ready to get dirty.....;.....
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REDBRICK, '96RS (formerly owned), K11OG#5
2011 Triumph Sprint GT
Not a turncoat...and do miss my special K

[Off the grid]

Just for the record my caliper does not wear evenly either even after a rebuild.

The outer pad wears faster, when it's dead the inner pad has about 1/4 life left.

That kind of wear I can live with without having to fork over the time and $$ for a replacement.
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Bane of your existence since July 2006
2007 Triumph Tiger ABS. "Sabertooth"
2009 Husqvarna TE610. "The dirty Italian mistress"

[planthead]