Brake Booster Problem?

[Xhlr8n]

got an 04,

the brake pedal is hard with little to no stopping power, checked for vac leak and couldnt find any, there is a hiss sound in footwell when brake pedal is pressed, is it the brake booster? anyone else have a simular problem?

tia

tom

 

[Racer Robbie]

Sounds like it could be. Check the tubing between the engine and the booster and make sure there is not a loose connection. Also check the one way check valve at the booster, it should only flow one way toward the engine. If everything is fine I would believe you have blown the diaphragm in the booster.