I have a set of Hope tech x2s. The rear caliper appears to have a sticky piston, as however I set it up, the disc always moves as the other piston hits it first.

I have only ridden them once, which I hoped might free it off but it didn't.

I have bled the brake in case it wasn't bled correctly from new, and have had the pads out and cycled the slightly sticky piston by holding in the other. I cycled it about 20 times, which slightly improved it but didn't solve the problem.

Is there anything I can lube it with to help it move as easily as the other piston? I had a search and it seems using brake fluid is a bad idea as once it dries it becomes sticky?

Cheers
Paul

Brak3e fluid will do – but red rubber grease is best. Centralise the pistons according to the method in the vid on the hope site – not by loosening the bolts then applying the brake

Hope used to have some silicon fluid stuff that you put on the piston seal, could try them to see if they still do it.

silicon grease on the piston seal – which is inside and you cant get at without the piston being removed.
Red grease may work bit as the sealermseals it is hard to get it past it to lubricate it.

Aye – a full strip is the best way to lube seals but I find getting the grease on a piston that is pumped part out helps.

do the hopetech piston set up – it is the best way
http://www.hopegb.com/page_mep_force_39.html

Well I have some silicone spray, so i'll pop the piston and put some of it on it.

If that doesn't work I will give Hope a call to get them to have a look at them

The hope centralizing the caliper has worked really well on the front brake – I am really pleased with that. Its just the back is virtually dead

Hmm done that and still the disc is moving :(. Both pistons seem to be moving now though.

Going to take it out for a ride and see if it is any better

Surely if they are really sticking, and not just set up incorrectly (as hope vid on youtube) It should be a warranty issue? If you bought them from a local shop i'd be trotting back there for them to sort!

Well it isn't sticky any more, they both move at the same time. However the pad clearance with the pistons pushed back is tiny. I set the clearance equal on both sides, however when I pull the lever for the first time, one bad doesn't retract as much as the other, so the next time the disc is moving.

I know it is not correct, but I tried setting hte pad clearance equal on both sides again, but it rubs constantly.

I am guessing the piston that sticks out must be a little tight so the seal doesn't retract it properly.

Think I'd give Hope a bell and send the brakes off to them to sort out.