r3pro Piston Release Tool
The r3pro Piston Release Tool is a genius bit of kit for servicing stuck or sticky four-piston Hope callipers. It makes an otherwise devilish job a piece of cake.
If you run a four-piston calliper, it’s highly likely that at some stage one of those pistons will get sticky and not want to advance at the same rate as the others. This leads to uneven pad wear and rubbing.
It’s easy enough to rectify this on a two-piston calliper but it’s more tricky with a four-piston design. This tool allows you to free up or advance a single piston at a time on a four-piston calliper. This particular one is designed for the Hope E4, V4 and RX4 callipers but other versions are available.
The tool is simply a block of plastic with a cut out area that lets one piston advance while holding back the other three. The tolerances are sub-millimetre, so the piston advances exactly as far as it needs to without risking leaking fluid. Whether the piston was genuinely stuck, a bit sticky, or you just wanted to be proactive in cleaning it up during a pad change, the tool does the job perfectly.
For £11.50 delivered, in one of nine colours, it's a bargain, and given the pretty much inevitable problem it solves both easily and quickly, a must-have for anyone running four-piston brakes.