[Closed] Stuck calliper on Juin R1...

clean around the piston with a sharp blade and lube with some shimano mineral oil ;

used to work for me but had to do it regularly ; especially at the back , never at the front ;

Had that on one of mine which was nearly a year old.  Cleaning wouldn't solve it so emailed the manufacturer asking for advice on how to unstick it and they sent out a new caliper without question. Good customer service from them.

Thanks for the info....was it the UK dealer you contacted, as I've had no reply from them!!

im having this very issue at the moment, my problem is that the brake is mounted on the chainstay - this allows water and crud to run down the actuating arm into the brake master cylinder itself. I stripped it last night and cleaned it out but also ordered the rebuild kit as they've been commuter hammered for 18 months or so now.

Glad you posted this, having the same problem. It's only on the back. The piston arm doesn't return and you can feel the grit inside the cylinder. I'm a bit pistoned off with it to be honest because they weren't cheap.
Didn't know there was a rebuild kit where's that from then?

Coupled with this disaster, my crank arm (FSA Gossamer) fell off on the way home so that's knackered (threads stripped), and my Prime Race Rear Wheel bearings have gone already, (<500 miles). Oh and the rear mech has seized to the hanger. The joys of CX!

Had this issue after only a couple of weeks of use, returned them for a refund and got Shimano hydraulics instead. Their calipers leaked (four in a year) now using Hopes calipers, good so far.

Rebuild kit from eBay or edgeukbikes (distributor) - £15 for the calliper and master cylinder seals

Cheers Rusty, had a look on Ebay,, as you say it's pistons and seals which for me aren't the problem sadly. Will take the caliper apart and see what can be done about that master cylinder.

If anyone has any reccomendations for single ring bb30 chainsets for CX I'm all ears too.

BENJIM

I read thst the seal kit contains the master cylinder o rings as well as the calliper pistons seals. I've also emailed the distributor about adding some additional sealing to the actuator rod as it's bit of a design flaw.

Thanks again Rusty, might just take a punt on the seal kit.

Thanks for the info Rusty.....

loved my mk2 Prairie 🙂

Another question on this after I've managed to unstick the master cylinder. How do you bleed them. I tied down the piston with a cable tie. Attached syringes with mineral oil to both ends and pushed through. this doesn't seem to have had much of an effect on the brake caliper. Any clues/ or pointers to a guide would be useful. Tried googling but came up with nothing.

Update to the stuck calliper.....problem turned out to be compressionless cable which was rusted inside!! According to my LBS cable did not have a plastic inner liner?