SC Brake issue
 

I drive my SC only periodically and have had an issue lately. I apologize for the length - if you hung around, I'd explain it to you in twice the time. :)

First symptom was a burning smell in the cabin that appeared within the first ten minutes or so of driving. I thought it might be an electrical issue and pulled over, popped hood, couldn't find anything in the fuse panel area as an issue. Seemed the fuel pump relay was a bit warm, but no other issues. Got back in the car, drove it a few more minutes and the smell dissipated completely.

Next time out a few weeks later, burning smell in the cabin re-occurs. I happened to be near an auto parts store and pulled in. Again, popped hood - no issues found. But then while kneeling lower, I realized the smell was strongest just above the wheel well - then it dawned on me. Must be a sticky caliper that was over-heating. Got back in car to drive home, and the brake pedal went straight to the floor when I went to back the car out of the parking space. I drove in the (almost empty) lot for a few minutes - the pedal would be firm after a few pumps. Then I would start out and stop again - pedal would be completely soft. I figured the heated brake fluid (standard DOT 3) must have boiled and got air in the system. This was the first time the brake pedal had acted in this manner.

I had rebuilt calipers with new pads, turned rotors, etc. about 10 years ago. I decided to order caliper rebuild kit for the front (ordered from Pelican Monday, parts arrived in ATL GA before lunch today - that is fast 3 day shipping! ) and just finished installation. I also replaced the soft brake lines. Brakes were bled and pedal felt somewhat firm in the garage. Took the car out for a spin - pedal goes straight to the floor in the driveway. :(

Seems consensus is this is a bad master cylinder symptom based on pedal behavior - but would that explain the symptom of the sticking pad/burning smell?
Edit - just realized I did not include that the dash brake warning light is also on.

You could have experienced both failures
> dragging brake caliper
> faulty master cylinder

definitely the burning smell from the front = dragging caliper - I had a bad caliper on my sons M3.. would run OK for awhile > then drag... then ok and more drag... I'd spit on the rotors to see how hot >> and sizzzle... rebuild of the caliper > cheap - just a few gasgets...

I'd replece the master cylinder > bleed the whole system again and see what happens

Perhaps your rears are dragging too. Could you stop the car at all even with the low pedal? If so ,then rears going away would leave a low pedal and still stop the car with your rebuilt fronts.