It sounds like you've got a mismatch between the master cylinder and the wheel cylinders like Rod suggests. If the master cylinder diameter is too big, there will be a very short pedal stroke and not enough hydraulic advantage between the MC and the wheel cylinders. Make sure your replacement cylinder is correct for the vehicle application- - - - -some low-IQ computer jockey at the local auto parts store might have tapped in the wrong info on his keyboard!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!