Brake booster cold problem
Cold morning problem
Got in car and no power brakes.
Took hose off the booster and there was lots of vacuum.
Let it warm up and then when the heat was on the floor they came back.
When they came back I could hear the "noise" of air when I pushed on the brakes.
I kept working them.
Noise went away and brakes are fine now.
I would say that it is the booster with a hole in the diaghram but why just when it is cold?