thanks for all the replies, i'll start from when i think it all began i'll try and keep it short so bear with me.
a few years ago i was doing a track day and the n/s/f brake wore down quite quickly due to crappy pads, the pad wore that thin that one of the pistons came right out of the caliper, removed the caliper refitted the piston, fitted new pads then bled the brake. this was fine for that year then the car sat off the road for a couple of years.
at the start of this year before the racing season started i ordered new seal kits & rubbers for the calipers stripped them right down & cleaned them out, fitted new bleed nipples & new braided hoses. i also fitted ebc yellow stuff pads & new brake rotors which were long overdue, bled the whole system with dot5 brake fluid, no air at all in system. i've now done 4 events this year and nearly everytime the drivers side has always got hot then started to stick but if it is left and cools down it free's itself off. the other day i had it to my mates garage for him to set up the apexi boost guage, once that was done he took it for a roadtest which was approx 1 mile possibly even 2 at the most and when he came back the front brakes were both locking on & the passenger side caught fire.
yesterday i looped the brake pipes at the abs pump and so far it seems ok, the wheels spin quite free so i'll roadtest it this afternoon and see what happens.
i hope you've not fallen asleep reading this!!! all your help and advice is greatly appreciated.