Fuel lift pump problems.

so..
Im really struggling with the fuel lift pump, my new pump arrived today and i just cannot seem to get any fuel through it, let alone to the fuel filter. I have checked that the cam isnt engaging with it and even tried pumping it whilst not bolted to the engine and i cannot seem to get anything though. anyone got any ideas?
i have tried plugging the pump in directly behind the fuel sender and can get fuel. i have then plugged the main fuel line into the fuel sender then to the pump and can get fuel to the pump this way so i know the fuel pipes are good and letting fuel though, its just once it is all joined together there is no fuel coming up. how hard should it be to bleed the fuel system, am i missing something really obvious. thanks.

I struggled to bleed mine.
Bought a hand vacuum pump and used it to suck the fuel from the tank to the outlet of the filter....no problem since.

.Turn the engine a little hand primer cannot work if cam has pushed the diapragm into up position,