Thanks for the reply, i did think that was my last resort but i didnt want brake fluid everywhere. I got em out now anyway.
Tip - (and the pistons were really stuck.)
First caliper -
1. I blocked up the hole in the caliper with a banjo bolt and a load of washers to cover the hole up.
2. Opened up the bleed nipple.
3. Attached a bicycle pump (high pressure stand up one) to the bleed nipple, with a bit of muscle it went on and sealed a treat.
4. Then I pumped it a few times thinking nowt would happen, at approx 200psi I thought i had been shot.......
one piston had literally fired out like a missile, the other hadnt moved.
5. Ended up butchering the other piston with some mole grips to remove it, it eventually came out.
I dont recommend the above as if the piston hits you it will cause damage. I was just lucky it didnt break anything. Also, if one comes out on its own, the other is simply stuck tight and will take a hell of a lot of work to get out.
2nd caliper,
As above for 1, 2 and 3.
4. I put a piece of wood between the caliper body and the piston so one didnt pop on its own again.
5. Pumped a lot, approx 250psi held in there for about 30 secs, released pressure and did it a few times, eventually one piston moved, but not all the way, just to the wood. With a lot more attempts the other piston also freed.
6, released the pump from caliper and prised out the pistons the last (about 5mm) bit with some pliers (with cardboard to protect the pistons.
Job done. I have all new seals and red grease to rebuild as soon as i have cleaned them up, i dont think they have ever had a bit of love and attention like i am going to give em !!
as for new pistons.......... I have ordered these, seem a bargain. thanks to Veefer400 on another thread for the following link.
http://cgi.ebay.co.uk/Honda-nissin-cali ... 500wt_1156