C2 service

I've just completed a seal change on one of my C2 brakes.
Problem is im still not getting the pistons to fully retract,im im completely lost as to why.
I'd heard putting some silicon grease on the seals prior to sliding the pistons in,but i didnt do this as it was not in the manual and i was unsure and didnt want to contaminate the fluid.
I think i can still smear some on if i push the pistons out with the lever and wipe some on.Might be just the seals are a bit dry due to being new.
Anybody else serviced these things? got any more tips to help me out?

I dont know why this isnt working right,i stripped the calliper totally,cleaned it out with thinners then sat in in a tub of hydraulic fluid to get it to work in to the nooks and crannies.properly bled and no air in the system.
I havent done a lever rebuild using their kit[i have one],i didnt think there was a problem as it wasnt leaking :?
Could it be the spring inside the lever that returns the lever piston?.a new one is included in these rebuild kits,im wondering if i should use it or not,maybe its just a bit weak to pull it fully back.
Lever springs back with no problem

The LBS mechanics are prodding me to buy a new set of formula k 18 or 24's,ive been desperate to show them how C2's can compare to the modern ones they have,wipe that knowing smile off their smug little faces
:twisted:

Silly question but did you screw the pistons back in again? If not they'll stick out a little way.

Yes ,fully screwed in
It could be the springs inside each piston has weakened or even down to the spring inside the lever,its possibly not worth renovating them due to time and cost
Decision made.
Im going to flog the lot off on ebay @ £25-30 BIN on each brake,leave it to someone else to get them running
then buy Avid juicy 7's from CRC and be done with it all.
http://www.chainreactioncycles.com/Mode ... elID=22187

one last possibility - there may be too much fluid in the system? Try opening the bleed nipple and see if any fluid comes out (catch it before it lands on your disc though...)

Ive been through that when you bleed,after you screw the cap back on it forces the pistons out.the last stage of bleeding these is to open the nipple again and allow the pistons to slide back then close the nipple again.

I think theyre fubar due to age,maybe it would work if you stripped the whole thing and started from scratch
I dont have the patience ,so someone else can do it

I'll sell them with all the bits to get them operational again