I stepped on the brakes, and stopped in the middle of an intersection.  The pads are good - this is a low mileage car.  The peddle goes to the floor.  I checked the brake fluid, and one of the wells was empty.

Yes indeed! both sides need to have fluid. You need to definitely check for leaks at the calipers and look around your master cylinder for leaks. Check your lines also. I guess what I am saying is do a thorough inspection of your brake system.

Yes!! If the pads have fairly low mileage, the wells should be close to full. Definitely something wrong there. Have a look at the short rubber brake lines on all 4 corners  if something suddenly let go and your foot went to the floor, they are a likely culprit...

It could also be that the rubber lines have collapsed from the inside.  Mine did and the leak was at the drivers side rear corner.  Couldn't tell it on inspection till it was off the car.  New steel lines and new calipers on all four sides will set your mind at ease.

[QUOTE=twocorvettes]...this is a low mileage car.... [/QUOTE]

Thanks for the input.  I guess its not a simple matter of adding the proper brake fluid.  DNV's reply is what concerns me; if there is air in the lines, then they need to bled.

You will need to fill the master cylynder and then bleed your breaks, during the bleeding process you can inspect each weel for leaks.I beleive the rear well is for the rear brakes. the perportional should have set to wichever side still has good brake presure giving you either front or rear brakes only. indicated by your dash brake light remaining on. if no evedence of leaks and the bleeding resets everything you can just keep an eye on the master cylender.

  I'n this Case a Low Milage Car is more likely to have Brake problems than one that is Used. It has probably sat for extended Times with Standard Dot 3 Fluid that has Absorbed Water. This Means that the Caliper Bores have Rusted and when the Car was finally Driven the Pistons were Pushed past the Rust and it Ruined the Seals. Sounds bad but it is a Typical Corvette thing that has happened to 1000's before. If water was in the Brake Lines long enough it can Rust out a Line to. The Low spot in the Crossover Line in the rear is the most likely to Go. For what ever reason You lost Brake fluid and Your going to have to find where it went. If a Caliper is Leaking then You will probably want to send it in and Have it Sleaved with a Stainless insert. There are a Number of People who do this. Vette Brakes and Products has served me well. For the NCRS I'd not do the Exchange Program I'd send in Yours and wait for there return. Tell them You don't want there Name Stamped on them Cause Your going to have the car Judged. Other than that there is no way for the NCRS to tell they have been Sleaved.  If Your not planning to Drive this Car much You should also think about switching to Silicone Brake Fluid as it dosn't absorb water. Had this been done 26 Years ago You wouldn't have any of these Problems You do now. Oh, by the way I replaced to Crossover Line and all my Stainless Jumper Lines today on my 80'.

Thanks Banks 80, that was really useful stuff, especially the information on how to stay as original as possible for NCRS judging.