Binding brakes

[Mellow Matt]

My OS front brake was sticking slightly, so I took the caliper off, greased the slider and made sure that the pads were free to move.

This didn't really help, so I pumped the piston out of the caliper a bit (not enough for it to come out), and then slid back the seal and cleaned up the piston with a bit of very fine sandpaper. It was a bit corroded, but not too bad.

I put it all back, and it's definitely better, but that disc still gets a lot hotter than the others.

If I were to take the piston out completely would I instantly regret it as it would prove impossible to get it back in, or is it not that difficult?

Also, the brakes are a bit spongey; would bleeding them mean that the brake piston in the offending caliper has more suction to pull it back in again after braking? I imagine the vacuum effect is stronger if there's no air in the brakes?

TIA!

[SixtySpeedTwin]

i had an intermittently sticky piston.
in the end it just got worse so i got it swapped for a re-manufactured unit.

i shopped about but in the end my local parts shop did it for £85, so now i have a lovely shiney caliper and free brakes.

[MG CHRIS]

Could be a collapsing brake flexi pipe. To check this try to push the piston back if it doesn't move back undo the bleed nipple try again if the piston moves back the flexi need to be replaced.

You can easily remove the piston by pushing it out using the brake pedal when it's out remove the calliper inside there is a big o ring seal remove it clean out any rust inside with a picky tool or small screwdriver, clean out with brake cleaner do the same for the piston then refit the seal and pop the piston back in.