89' XJ Brake question

Okay, I just acquired an 89' larado 4x4, most everything works but I have question regarding the brakes. I see that it has 4 wheel ABS on it, seeing that this is a dinasaur compared to whats out there now, can I bypass the ABS and run just a standard power brake system? This because I have almost no braking ability, master cylinder is full. Could this be signs of a ABS system problem?

Have you checked all the various components? IE- break pads, rotors, etc...
How's the pedal response?
ABS systems are designed to stop vehicles faster/better than standard systems from what little I know.
Good luck!