This morning my 2003 2500HD started making a noise when going slow and turning the wheel. It sounds like a vacuum leak coming from around the steering column area, and it only happens when I put pressure on the wheel to turn, or turn more, but not when rolling without changing direction. It will happen while parked with the engine running if I just grab the wheel to turn. PSSSSSSSSSSSS. It will instantly stop if I depress the brake pedal.
What could this be? I'm guessing something with the hydroboost since that seems to be the system that the brakes and steering have in common.
I have 26K miles, so this will be a warranty issue, but knowledge is power. I like to know what is going on before I go to the dealer!
BTW, it seems like operation is OK at this point, maybe a little strange to steer when going very slow.
While I'm there, maybe I can get the steering shaft rattle, falling headliner, faulty seat positioning module, wimpy AC output, and the recall issues all addressed.
Any help is appreciated.
:help:

I've got the same problem. Dealer said it was a line rubbing at the hydroboost. Put a new grommet on, but did not help the situation. I'm at 34k, and worried that the power streering pump, or some other big ticket item, is going to die right after 36k. Sorry I don't have any answers, but I would appreciate if you would post if you find any solution from your dealer.