Hello,
Yesterday I was out driving my 77, got an oil change, and everything seemed normal. This morning when I get into drive it, my brake pedal almost hit the floor, and the emergency brake light was on. I just backed it out, and drove a few feet. You could tell that the pedal had alot more travel than usual. When I got sometime to look at it today, I saw no visual leaks, I held the pedal down when starting it, and noticed that it still was assisted, and I checked the master cylinder. The master cylinder didnt seem quite full, but the strange thing is that the 2 rubber pieces that hang down from the cap were smashed. I straightened them out and started the car, and now the Brake light is extinguished, but the pedal seems to travel too far. Sorry for the long post. Any help is appreciated.

 

You have a leak somewhere. I would bet a caliper. You may have to remove and look at them.

 

No need to worry about the rubber pieces. They should be flat until brake vacuum pulls them out. They may not always pull out perfectly smooth. If you have soft brakes air or lack of pressure is the cause. If you find no apparant leakage you may have a master cylinder problem. The first thing I would do is run a proper bleed sequnce per the GM shop manual. The sequence is critical and is not the normal farthest to shortest sequnce. Make sure to consult the manual. I had a similar problem where intermittenly I would get a soft brake which was immediately followed by a hard pedal. After much work I dtermeined it was the master cylinder. I chose to rebuild mine to keep numbersw match, and found that the seals were flat spotted and sludge filled the bottom of the cylinder. It is cheaper to replace the whole master cylinder, but beware, I have read many horror stories of many bad ones right out of the box. Make sure you bench bleed a new master if it is replaced. Before gong the master cylinder route you may want to at least pull the calipers and see if you have seepage. Any small leak can cause a soft pedal. You may find one that is seeping. If so you will need a rebuild done or replace the calipers. If you need to rebuild/replace one or more, you would probably want to change the rubber lines leading to the calipers at the same time if they are old. Good luck!