I have noticed that some days the brake pedal will almost sink to the floor, other days it is quite firm. I always set the parking brake. I took the car to the dealer and they added a small amount of brake fluid, which seemed to help for a day or so. Has anybody else run into this? Any help would be appreciated.

 

Sounds like a problem that'll take more than a bit of fluid to fix. I've not yet experienced this but if I did I'd be at the dealer that same day and wouldn't take the car back unless the explanation/fix is good.