The Magura MT5 caliper on my front wheel has developed a really irritating issue.
Fine at the start of a ride but very soon the outboard piston(s) start to creep towards the rotor. First there's a slight whistle as the pad just touches the rotor, that then develops into a squeal, and finally a binding noise that can also be felt through the forks/bars. Flicking the front brake temporarily cures the issue but it soon returns.
Removing the wheel and manually 'resetting' the pads/pistons does the trick until the front brake is used again.
Caliper is centred and disk is straight.
Anyone had this and cured it? Anyone got any ideas?
(my initial thoughts were sticky pistons or somehow too much pressure in the system?)
Sticky piston...
Take out pads, extend the piston as far as you can (without it popping out!), give it a good clean with cotton bud and a drop of lube, add some red rubber grease and work the piston in and out.
Totally cured the same problem I was having with my Hope X2s
*Edit
Unlikely to be an overfilled system if both calipers will push back fully.
However, I once had some brakes that from new the pistons wouldn't retract fully. You'd push one back and the other would extend a bit.
Opened the bleed port and let a bit if fluid out and it was spot on afterwards.
Probably a sticky piston. Possibly air in the reservoir expanding with heat. Pushing the pistons in and then opening the bleed port in the reservoir should let any air escape.