coupe d'mike

i've got a constant audible hiss coming from my brakes. it starts making noise after the car is running for a few minutes. when i push my pedal down half way it goes away. i thought it may be the master cylinder, but this guy at a shop said its the check valve bleeding vacuum. my brakes work fine. when i turn the car off, the hiss slowly goes away. thoughts?

rabbid

my memory is hazy on this, but doesn't the cruise control use vacuum lines?

Take a look at the brake pedal - look for a vacuum line going to a switch. If I am remembering right, you could have a leak at brake pedal...