Ok, I am a Master Certified Auto tech but these combo brakes are really pissing me off, mainly because there deflating my self image of being a decent wrench!
Here's the abbreviated story. I finally decided to replace my brake pads front and rear. I cheaped out and used aftermarket pads but they appear identical. We'll now I have a slight drag on all brakes that causes rotors to heat up while riding even when not applying brakes. The bike rolls fine and the wheels turn by hand but there is a detectable slight drag. My first thought was retracting the caliper pistons had caused piston crud to bind the pistons. So I removed all calipers and pistons. Cleaned and polished all pistons and bores, inspected and cleaned seals. No new seals available locally. Pistons seemed to move easily at least compared to auto calipers I have rebuilt.
Put everything back together and all brakes still have slight drag. Next I loosen hoses and bleeders and brakes seem to free, I then disassemble and clean the rear master, secondary master and bleed out system again. Guess what, still slight overheating drag. I discovered that my loosening the bleeders and lines did not really loosen caliper but it was the twisting action on caliper that loosened the drag. Next I tried the old worn out pads again, still dragging. I've checked for pin binding and proper pad fit and all appear ok. My next step is to order all new seals and fully rebuild all calipers with Oem seals even though I haven't found any corrosion. Sorry for the long post if you've made it this far!
This easy job has used up two days of my vacation and I would love to buy a steak dinner for someone that leads me to a fix!
Here's the abbreviated story. I finally decided to replace my brake pads front and rear. I cheaped out and used aftermarket pads but they appear identical. We'll now I have a slight drag on all brakes that causes rotors to heat up while riding even when not applying brakes. The bike rolls fine and the wheels turn by hand but there is a detectable slight drag. My first thought was retracting the caliper pistons had caused piston crud to bind the pistons. So I removed all calipers and pistons. Cleaned and polished all pistons and bores, inspected and cleaned seals. No new seals available locally. Pistons seemed to move easily at least compared to auto calipers I have rebuilt.
Put everything back together and all brakes still have slight drag. Next I loosen hoses and bleeders and brakes seem to free, I then disassemble and clean the rear master, secondary master and bleed out system again. Guess what, still slight overheating drag. I discovered that my loosening the bleeders and lines did not really loosen caliper but it was the twisting action on caliper that loosened the drag. Next I tried the old worn out pads again, still dragging. I've checked for pin binding and proper pad fit and all appear ok. My next step is to order all new seals and fully rebuild all calipers with Oem seals even though I haven't found any corrosion. Sorry for the long post if you've made it this far!
This easy job has used up two days of my vacation and I would love to buy a steak dinner for someone that leads me to a fix!