No, it's usually a vented cap design.
bad master cylinder
The power brake booster may be going bad.
This sounds like the power brake vacuum booster going bad.
Your idle will jump up and down. You may also feel a misfire, due to the vacuum leak. You may also hear a hissing sound from the engine. Nice job you nailed it. But if you hear no hissing, you can spray some brake cleaner around the intake manifold. You'll definitly hear it. The cleaner will remove any crap blocking it from the hissing. Easiest gasket to replace.
if your vehicle is fuel injected there is a good chance your fuel regulator is bad wich will cause boiling of fuel in the injector rails, also your canister may have become fouled it is usually under one of the front fenders, Brandon
Power brake booster is going bad. wont hold vacuum for power brakes to work.
It's bad. It makes you sound like a fool.
Vacuum leak or bad vacuum motor under dash
IT is your CV Joints which is making this noise.
bad wheel bearing.
If it makes a boiling sound when it comes out then it is probably a bad radiator cap.
They are NOT bad they are good.