Rear brake pads after 4500 miles

[JimB]

07 FLHX - Been chasing a problem on rear brakes.
At 1700 miles I burned the rotor up with the original HD factory pads, warranty replaced the rotor, rebuilt the caliper & new fluid
Swapped out the HD metal pads that were about 80% gone for EBC Kevlar at 6200 miles = 4500 miles
Now, 4500 miles later the EBC pads are about gone too but rotor is fine but the wheel was covered in brake dust

Pulled the rear caliper, replaced o-rings, cleaned & lubed caliper pistons, didnt see any thing that would be usual - no scratches or marks
Pulled the piston out of the rear master cylinder assembly, replaced piston assembly, didnt see any other issues, replaced fluid
Installed EBC HH Pads this time

I do use the rear brakes but Im not a rear braker & the front Lyndal Z pads are at 8800 miles & just fine

Suggestions as to what maybe the problem ?

[surf]

Bad rubber brake like? Inside could have a damaged/seperated area that acts like a valve and wont let the pressure release. Had it happen on old trucks.

[Bakon]

Are they always touching? can you spin the wheel with it on a lift? Check for drag somewhere in there.

[JimB]

Theres always a light drag on HDs calipers
Checked the wheel spin while on a lift before & after I did the recent work... no drag more than normal
Could always be the hose, after the recent work, its the only thing left I havent replaced...