problem solved.... got a new lever body, piston and seals off a mate. works MINT!
I did bled it with oil, as my dad didn't like the idea of water. no luck. So i cut the orange dirt seal off, (square one?) and popped the piston back in, no better. cut the o-ring off. no better. Even tried it with no seals. Just as a test. and it was still sticking. So I'm going to say its the piston at fault. But I have a awesome brake now. Trials-tech splitter is very nice. makes both pistons move together.