faulty brakes

I have a 1992 Mr2 n/a and sometimes when I press the brake pedal it sinks to the floor without actually braking until the very last minute. But if I press it down a couple times it works fine, so most of the time I have to press 2 times for the brakes to work properly. Anyone had a similar problem? what might be the cause?

air bubbles, just bleed your brakes.

bleed the lines or from the master cylinder it self? what about the lines that go to the wheels, would I have to bleed them too? thanks.

I would think it might be the master cylincer going out.

a master cylinder costs a bit more than a jug of brake fluid... i would bleed the brakes from the wheel lines, and if that doesn't fix it then look into a new master cylinder.

thanks for the input guys. hopefully i just need to bleed the lines.