PX Hydraulic Front Brake Problem

[mark-b]

Hi, one of the pistons in the hydraulic front brake caliper on my PX is stuck. The piston is pretty much as far in as it will go, any ideas how to fix or do I need a new caliper? which is not good as it will cost £70+ to replace with a new one.

Cheers, Mark

[wack 63]

With the caliper off the carrier but still connected to the brake circuit and holding the free piston with grips or clamp try pumping the piston out.If this doesn't work try compressed air if available and failing that,split the caliper down by undoing the Allen bolts.Inside the two halves are sealed by small O rings,remove these and block all holes off with fingers and rag and use an air line to blow into one of the small drillings.This will usually do the job but beware of the piston flying out.WD 40 sprayed onto the piston to soak in will help.Once out clean everything up especially the piston seal groove and replace all seals and piston if damaged (try Beedspeed etc).It's a job that can take hours sometimes

[mark-b]

Thanks for the info Wack, bit the bullet and ordered a new caliper as a lot easier and I imagined that the piston might be damaged from corrosion, wallet's 70 quid lighter though sadly.

Cheers, Mark