2000 tundra pedal goes to floor

[00Tundraman]

I have had this happening for quite sometime now, i figured it was always due to worn front pads and rotors so i did a full replacement in the front. After the job the pedal has made no significant difference. I checked the rears and everything was good and adjusted except for the parking brake is froze up. I dropped the truck off to tuffy and they claim that the rear proportioning valve has gone bad.

any ideas where to start?

thanks

[scaryperson27]

Sounds like your master cylinder is on it's last leg. I would change it out and bleed some good break fluids through the brake system.