K11 Owners Group

[nickw]

Have been enjoying the decent weather here in the Northeast after the wettest spring on record. Mnaged to ride for seven days in a row without getting drowned. Quite an acheivement at this end of the country.

My mileage started dropping and I began feeling a slowdown like a cylinder dropping out after about five miles, not sure what was going on until I tried parking where I had to back up a bit. Not so easy, front wheel tough to rotate. Effect seemed to come and go during a ride, would free up like a cylinder came back on line after about ten miles and then seem fine for twenty more. Did not appear to be related to use (or not) of front brake.

Investigation: left disc hotter than right but not untouchable. With wheel off ground, wheel will rotate, but left brake is dragging. (proved it was brake by retracting pad(s) with small pry tool.)

Action1: Read all threads on K11Og. (Took quite a while)
Action2: Buy Speed Bleeders for all points
Action 3: Buy new pads for front calipers.
Action 4: Test for residual pressure in caliper to determine if hose is at fault. Result; no spurt, no change in drag.
Action 5: Push pistons in while ensuring M/C does not overflow, replace pads on left caliper and re-test. Result; No drag! repeated attempts to make it stick convinced me that I had solved the issue withouit buying the expensive caliper rebuild kit(s)
Action 6: Replace pads on right caliper to ensure both calipers have the same pad life and friction materials. Result; right caliper now exhibits dragging brake exactly as left was when I began this little effort!

A 20 mile ride confirms that the pads are seated correctly and bearing correctly, the right side disc temp is now showing higher by 150+ degrees after the ride.
Background: Fresh fluid, clear at bleed screws, no M/C sticking evidence.

I suspect I have not dodged the bullet on these (expensive) caliper rebuild kits.

Any thoughts?

Nickw
_________________
"It's not what people know, it's that they know so much that just ain't so!" (Apologies to Will Rogers)
93 K1100LT
(2) 79 Suzuki GS850's (In limbo)
65 Triumph TR6S/C ( sold)
2009 Suzuki SV650
2009 Suzuki DL650

[Scott_Anderson]

My 1st thoughts would be you are due for a caliper rebuild. x2
I think I'm due for the same thing on my '95.
Not having pad drag, but having fairly obvious uneven wear.
The last time I changed the pads the thickness was far from equal. Side to side or left to right. I'm probably going to get by this season and plan the rebuild this winter.
_________________
Ride safe.



1995 K1100LT 0302044
2017 FLHTK Ultra Limited
Garmin StreetPilot 2820
Garmin Zumo 550
Garmin Zumo XT
"One who does not ask questions is ashamed to learn" Danish proverb
1997 K1100LT 0302488(R.I.P.)
1997 R1100RT ZC62149(sold)

[Christopher P.]

My K100 brake problems were not in the hoses, or calipers - it was the master cylinder piston. Replacing it solved my grabbing brakes. The issue was vibration would let fluid blow by, slowly increasing pressure in the system, but it was one-way. You might consider a rebuild kit for the MC, or replacing it if an inexpensive one is sourceable.
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www.tidewaterforge.com

[Stoked Steve]

One other thought is older hoses that are deteriorating on the inside..

Seems I've read of some developing a "flap" of rubber inside the line that acts like a one way valve, allowing the fluid to go one way (activating the brakes), but not allowing the fluid to return, thus not fully releasing the caliper.

Another thing you could try is just disassembling the master cylinder and give it a good cleaning, especially the bore of the piston tube with some fine steel wool. I think Duck has restored a set or two with this method.

I did a master cylinder rebuild on the front a few years ago and it has worked fine since then. I know those kits aren't cheap, but they aren't that much. I don't play around with brakes.

I just had one of my hoses on the front set, the ones that run RIGHT next to the tire, finally wear through where it had rubbed on the front tire a bit. Fortunately it happened in the driveway while trying to bleed to brakes to eliminate some sponginess in them.

I'd advise everyone to check that area carefuly and make sure your lines are not rubbing on the tire. Those hoses are $48 each from BMW.
_________________
Steve
Virginia Beach, VA
93 K1100RS Mystic Red SOLD
12 Suzuki DL650A VStrom

[nickw]

Thanks for the replies. I managed to steal a couple of hours yesterday to go further into my left/right dragging issue.
I removed the right caliper, took the new pads out and measured the thickness: both pads (by CL brakes) meausred .330 thick. The old pads (by Brembo) measured .310/.315.
I then took the caliper completely apart and cleaned it with alcohol and re-assembled it with fresh fluid as a lubricant. I found a very small amount of crud around the piston at the outside by the "dust" seal, but there was nothing inside and no corrosion or wear evidence on the pistons or the bores.
I had noted that two of the pistons on the inside were protruding more than the outside pistons when I removed the caliper, so I re-assembled the caliper sans pads, and measured the clearance from the piston to the disc on both sides; at the outside, the clearance was .320,on the inside about .450. trying to slide in the new pads @ .330 caused the slight binding I was experiencing. the old pad at .310 slid right in. I re-assembled the caliper with the old(brembo) pads and there was no drag. Using the new speed bleeder screws, I got the air all out and got back to a firm brake action, no drag either side, but a question about why the pad mount seems asymetrical. Checking the disc mounting shows no shims, no shim at the caliper mount and a firmly installed axle makes me think I might have an incorrect spacer at the axle mount?

Obviously I do not want to ride with mis-matched pads, so the other side is next on the agenda.

Nickw
_________________
"It's not what people know, it's that they know so much that just ain't so!" (Apologies to Will Rogers)
93 K1100LT
(2) 79 Suzuki GS850's (In limbo)
65 Triumph TR6S/C ( sold)
2009 Suzuki SV650
2009 Suzuki DL650

[nickw]

Got back to it yesterday for a few minutes. Repeated my efforts on the left side and re-installed the Brembo pads. This side not as asymetric as the right. measurements show that either pad set will fit with ease.
After bleeding system again, all was fine. Backing the bike out of my garage, I realized that now with cleaned calipers and non-sticking pads, that the brakes have probably been dragging some since I acquired the bike! It rolled so easy, I almost dropped it!.

Test ride 20+ miles, no dragging excellent brakes. When I returned to the nest, I found the M/C leaking a few drops from the housing.

Cleaned the housing, removed the switch cover and cleaned out the resident gunk with alcohol. No active leak with M/C actuation, so laid it to the heavy pumping action require to fully bleed the system, and possible overfilling/spilling at the reservoir during that activity.

Brakes OK, Don't believe all you read in Clymers about seals

Nick W
_________________
"It's not what people know, it's that they know so much that just ain't so!" (Apologies to Will Rogers)
93 K1100LT
(2) 79 Suzuki GS850's (In limbo)
65 Triumph TR6S/C ( sold)
2009 Suzuki SV650
2009 Suzuki DL650