Sounds like you have a bad vacuum booster. The hissing sound you here is it leaking when your pushing the pedal. The engine staggers because of the vacuum leak created by the booster, your pedal is hard because you have no assist from the booster.
~ Craig 1958 Viking 4400 "The Book of Thor" Read the story in the DITY 1960 Chevrolet C10 "A Family Heirloom" Follow the story in the DITY Gallery '59 Apache 31, 327 V8 (0.030 over), Muncie M20 4 Speed, GM 10 Bolt Rear... long term project (30 years and counting)
If you don't like driving yourTruck, you won't drive yourTruck..| Living life in the SLOW lane
