Rear brake disc heating up

[bizzaro]

So I hardly use my brakes, but the rear caliper drags just enough to to get the disk really hot. If I ride hard when I stop it has that contracting ping noise that metal does as it cool's down.  Does this mean a caliper rebuild, or can I just exercise it by making it move further in and out than it is now moving?

[johnny]

greetings bizzaro...

sometimes motobricks burn to the ground because of dragging rear brake...

id figure it out pretty fast if it was me...

generally its the pedal not returning... i would take a close look at the pedal mechanism first... then bleed all the old brake fluid outta there with new brake fluid... then i would pry the pads apart... ride it around the block...

then work the pedal while looking at the pads while spinning the wheel... your piston maybe hanging up... new fluid can fix that... or not depending... may need a caliper rebuild...

proally has to to with pedal and piston... although degrading oem rubber brake lines have been known to cause this too... lotts of whack in old rubber brake lines...

j o

[bizzaro]

Thanks Johnny.  Yea I am planning a trip to CO for a wedding in a month and really need to get some stuff resolved.  And this is one of them.  I have never seen it get red hot, but it does drag just a bit on the center stand. Which of course when riding will heat it up and make it expand  to exacerbate the issue.  I will check the pedal. And before my trip intended to bleed the brakes and refresh.  Is it necessary to do the abs as well or is that system less apt to be a problem? (shit they only work about 33% of the time anyway! And I don't have that connector to check in Frankenducks maintenance thread?  Difference in the k75 and K1100? if the lines need replacing it will be braided SS.

[johnny]

this is what i do...

abs modulator... the front nipple is the rear brake... the rear nipple is the front brake...

open end wrench on abs nipple... clear vinyl hose zip tied to nipple going to bottle on ground...

open abs nipple... slowly push pedal down... close abs nipple... slowly let pedal return... repeat while keeping the master full of fresh fluid... when you get clean fresh fluid out the abs nipple you are good...

closed end wrench on caliper nipple... clear vinyl hose zip tied to nipple going to bottle on ground...

open caliper nipple... slowly push pedal down... close caliper nipple... slowly let pedal return... repeat while keeping the master full of fresh fluid... when you get clean fresh fluid out the caliper nipple you are good...

if you getts any black specs outta the nipple you gotts brake line degradation and the lines should be replaced... if its the piston you will getts pedal return butts still pressure on the pads... this will only getts worse...

spiegler brake lines...

j o

[bizzaro]

Again, Johnny, you are a peach.  Yea, that is pretty much the way I have done it in the past.  I guess there is bleeder cup you can use that makes it much simpler.  I may try that out.  Especially doing the abs along with the regular system.

[beemrdon]

You might try changing out the rear flexible brake hose, as Johnny says. They rot from the inside and the debris can act like a check-valve. Happened to me.