I have four wheel disc brakes on my '82 T/A. Last week I changed the rear pads, put in new Dot3 and bleed the brakes and it was working fine until today. Now my pedal goes all the way to the floor and the car won't stop. I believe I need a new master cylinder and it's a slight possibility one of my rear calpers is frozen. Can anyone suggested a good master cylinder to buy? And before I get all dirty installing it does anyone think it might be something else?
Thanks

 

Have you checked the fluid level in the master cylinder to see if you have a leak and are losing fluid? You may also try rebleeding the brakes just incase you had some air left in there.

 

I just realized I am leaking fluid. I had to refill it yesterday but I just refilled it saturday and blead the brakes. Then I realized a intresting puddle under my engine this morning so I'm guessing the master cylinder is shot and leaking.

 

Also my rear passenger cailper has seized. Can this be a result of a bad master cylinder or do I need to get a new cailper?

 

I would fix the leak then rebleed your brakes and see if the caliper works then. If it doesnt you might check the rubber rose that connects the brake line to the caliper if its weak it could be collapsing and not allowing the fluid pressure to release from the caliper.