[Closed] Brake Leak Problem

Hi,
I'm having trouble with my Hope Mono M4 front brake. It's lacking in power and if I pull hard the lever nearly touches the bar.
I have tried fitting new pads, re-bleeding the brake and even replacing all the fluid in the system as I thought it might be contaminated. After the rebleed at first it felt better (although still not full power) but this gradually got worse as I rode up and down the road a bit.
I have had a look for leaks and can't see any but could there be some air getting into the system that I can't see somehow? Could changing the hose help?
Any help much appreciated, many thanks, Clwydrider JNR.