hi guys
I have a 2005 caravan 3.3L when I start the van engine noise is good even when I drive but when I stopped on red light push the brake humming noise will start then I can feel the vibration and as soon as I release the brake or put it in nutral noise is gone so can u pls tell me what need to be fix to get rid of this noise
thanks.

 

I am going to say that the brake booster has a torn diaphragm. To verify this, go to the parts store, pick up a pack of multi size vacuum plugs then pull the big vacuum hose that goes to the brake booster. (pull it off of the intake manifold T fitting) Put the plug on and see if the noise goes away. Be careful when driving as without the brake booster, the pedal will be hard to push and stop the van. I recommend doing this in an empty parking lot as it seems that your problem is easy to reproduce and this will cause no risk of you being surprised at how hard the brakes are with no booster.

It the engine noise goes away like this, then the booster is bad. Let us know what the outcome of this is when/if you try it.