1999 Chevrolet Malibu - brake issues

replaced master cylinder blead brakes still pedel still goes to floor?

Either you didn’t get the brakes bled properly - including bleeding the master cylinder first, all 4 wheels next or you have a leak.

The best way, is to bench bleed the master before you install it.

Yosemite

If the vehicle has ABS, the brakes must be bled using a pressure bleeder when the brake system is opened up.

Tester