Did you first use a master cylinder bench bleeding kit to remove the air from the master cylinder before connecting it to the brake lines; or did you just bleed the system at the connections from the master cylinder to the brake lines; and or at the wheels?
If you did not bench bleed the master cylinder before hooking it up to the lines; this is why it does not work properly. New master cylinders MUST first be bench bled before use. Bench bleeding kits are commonly sold at a low price by better auto parts stores. This kit contains 2 plastic hoses, and an assortment of adapter fittings to connect the hoses to the master cylinder outlet ports. The hoses are then routed up over the top of the brake fluid reservoir; with the ends submerged in the fluid; and secured there with clips that come in the kit. The brake pedal is then pumped; until air bubbles stop coming out of the hoses. The hoses and adapters are then removed; and the master cylinder then connected to the brake lines. The brake system should then be bled from each wheel; starting with the rear wheel on the passenger side; moving to the rear wheel on the driver's side; then to the front wheel on the passenger side; and finally to the front wheel on the driver's side. This will purge the air that was introduced when the lines were not connected to the master cylinder.