If anyone is interested, and for reference, I email trp and got this reply:
Thank you for the email. Other than a bleed and a piston exercise, I don’t have many other suggestions. Exercising the pistons:
Start by removing the pads
Use a tire lever, or box-end wrench, or something to hold the freely-moving piston in place
Actuate the brake to get the sticking piston to move out slightly - no more than 3mm, as you don't want it to pop all of the way out.
Use a Q-tip and mineral oil to clean around the piston. The mineral oil will also act as a lubricant.
Use the tire lever/box-end wrench/etc. to push the piston back in.
Hold the other piston in again while actuating the brakes to push the sticky one back out.
Repeat 5 & 6 a couple of times. Do the same with the other piston, so they're both starting over clean and lubed.
Bleeding: this is essentially a mtb brake, without a hose, and the lever assembly fused to the caliper. So your bleed will be very similar to this: https://www.youtube.com/watch?v=cS0pBCBT65g
(I don’t have a current bleed video for the Hy/Rd – coming soon!)
Going to try this out and see how they perform. Will probably use shimano brake oil unless anyone knows why this would be a really bad idea, as I'm going to buy a big tub and do the MTB brakes too.
If anyone is interested, and for reference, I email trp and got this reply:
Going to try this out and see how they perform. Will probably use shimano brake oil unless anyone knows why this would be a really bad idea, as I'm going to buy a big tub and do the MTB brakes too.