1994 Nissan Sentra SE, Standard Transmission: 1.6 engine, front disc brakes, rear drum

I drove last night for about 20 minutes in a snowstorm with my emergency brake 1/2 way or more applied. Didn't notice because the roads were in such bad condition and my light (I discovered) does not work in the dash. Did notice when I got out, brakes were smelling bad and smoking slightly.

Anyways, when I got to my destination, my brake pedal went down to the floor. Even when I stopped the engine and started it, the pedal would go down. Pumping it brought it back for a bit. I left it for about 1-1/2 hours, started it up and the brakes were back to normal. Brake fluid is still full. I pulled the drums off when I got home and brake look fine, except for more black dust on the wheel cylinder. Checked them and the wheel cylinders work fine along with the emergency brake. Checked brake lines and there doesn't appear to be any leaks. Hard to tell on this for sure 'cause everything was soaking wet. Brakes are working fine this morning.

What happened? Is this something I should be worried about or was it a "twilight zone" episode. My theory is that the drum brakes locked in the engaged position with the emergency on, and the wheel cylinders had too much travel room to be effective. However, I couldn't feel any stopping effort from the front as well. Also, in normal circumstances, when you pull the emergency brake, your brake pedal still has resistance.

Again, need help with this one.

thanks

 

check everything again when it's dry. if you see no leaks, your master cylinder could be going bad.

 

Spoke to a mechanic today and he figures I boiled the brake fluid. Symptons I described all point to this and I think I agree.