02GF74
Über Member
I'm curious, with mechanical discs you can pull the lever wheel in or not and the pad retracts, yet with hydraulics the pad retracts when there's a rotor in there but not when it's absent. Why is that?
The pistons will retract in hydraulic systems else each time you applied the brakes, they would never unclock.
The system is designed so that when the lever is released, the pistons are pulled in by the hydraulic fluid. If the pistons go too far out, i.e. there is no disc to limit how far out they go, they cannot be pulled back enough so that gap between them closes.
This is a good system as it takes up any wear in the pads and disc - mechanical systems need adjsuting.