you need to bench charge your mastercylinder.......set it in a vice and fill with brake fluid....then set a can under the front of the mastercylinder........then push on the brake piston lever...fluid should squirt out front of mastercylinder into pan...then before you bring lever back put your finger over front hole so that you dont get any air back in cylinder...then repeat the process until all air is out...you will have to add brake fluid after 1-2 pumps.......then you will know for sure that it is working.......if the master cylinder is working fine then install it.....then if you pump the brakes and get nothing you may have a blocked line