rear brake whack - what next?

[herseyb]

80,000 mile K1100RS ABS rear brake started getting hot a couple months ago.  Started pinging after riding around the block and the dust boots melted to the pistons.

I have tried:

Flushing fluid (negatory)

Cleaned pins which were gunky and rusty. (Negatory)

Replacing hose from resevoir to MC - all other hoses had been replaced with braided lines (negatory)

Measured lateral runout with dial caliper, .003 max deflection, within spec.

I just finished rebuilding the caliper and putting new pads in, since the old pads had not worn evenly.

Now I am spinning it around by hand and I still hear the pads kissing the disc for about 1/3 of travel, same spot each time after applying brakes.  Same pattern as before rebuilding the calipers.

Got the dial indicator back out, still seeing minimal lateral error, nothing beyond spec.

Should I try bedding these pads in or is that a false hope? 

Only thing I haven't done is fux with the master cylinder.

Time for a new master cylinder/ MC rebuild?

upgrade to comprehensive insurance and ride it around hoping it spontaneously combusts?

[Laitch]

Do this then follow EBC's simple bedding-in guidelines here. The steps to take are to check the brake pedal linkage to verify that it's set correctly, then determine if the master cylinder piston is retracting. My moto's cylinder has a helper spring but the piston was retracting ok before I replaced the missing spring. If the piston isn't retracting, disassembly and cleaning would follow. A rebuild might not be necessary. This is a symptom that drags owners down the rabbit hole. Don't let that happen to you. 

 

[herseyb]

still touches the disc during a portion of the cycle after putting new seals in the caliper, but it no longer gets hot.

success and out of the rabbit hole!  vrrrrmmmmmmmmm!