Hey every one. Had this car come into my little shop to go to many times. I’ve changed every vacuum line that I even heard a hiss from changed the air filter fuel filter intake gasket idle air control new ac new. I hear one more hiss under the brake slave but can’t determine if it’s the little black box that has b/b a/c writing on it sounds like it’s def lower that that hitting the brakes doesn’t affect the idle running the ac at a stop after hot will stall it. There’s a bunch of stuff there I can’t get my hand on the brake booster hose where it connects to the booster itself would that one small hiss cause the issue only after hot?