Hydraulic brakes rubbing

[Kestevan]

My GT has Tektro Auriga hydraulics. No problem at all with the front, however I cannot stop the back brake from rubbing.

I've pushed the pads back in with a flat screwdriver which opened up the gap, however as soon as the brakes are applied they start rubbing again.

The rubbing only looks to happen on 1 pad (the piston side), and it's not enough to have much affect on the wheel, however it's chewing through the pad on that side at a terrific rate.

It's getting to the point where I can't afford to ride the damn bike, a £15 set of pads is destroyed in a single 20 - 30 mile ride.

Any thoughts on how to stop it?

 

[andyhunter]

sounds like your brake is seizing which build up of dirt and grime and little maintenance causes this i.e. when you apply pressure and close it then when you release pressure it remains locked. You will need to take apart and do some maintenance i.e. cleaning. oil, lubing and or replacing of parts.

 

[lordjenks]

loosen of the caliper bolts so the brake capalier is looser, squeeze the brake and this with center the caliper, now whilst still holding the brake tighten up to bolts, now when you release the brake the caliper should be perfectly straight.
if you still get rub then you may have a bent rotar which you will either need to unbend( quick hard) or buy a new one.

 

[Kestevan]

Brakes are centred and the rotor is straight (AFAICT) - the rubbing is pretty constant throught the wheel revolution.

The brake is as clean as I can get it. There is no sign of undue friction or seizing. If I operate the brake with no pads I can see the piston moving easily, and there is little resistance if you push the piston back in with a flat bladed screwdiver.

Someone suggested that the fluid level may be too high, he suggested draining a couple of drops of fluid from the system and re-trying..... does this sound plausibe?