1996 Other Ford Models Ford Fiesta 1.4 Zetec Brake problem

Hi my sons car is the above the brakes were not very good when he bought the car so we bought new shoes for the back and new pads and disc's for the front(old disc were very very worn) but after doing all this the brakes are still not very responsive. the servo does seem to work checked putting foot hard on brake peddle then starting the engine the peddle does go down a bit further.
Any sugestions please

thanks very much

alan eaton