related quest for hissing noise stops when brakes depressed or steering turned on 2008 Dodge Ram 3500

I have about 600 miles to drive to get to a good dealer, any problens with driving this far. with vacuum like hiss?

Asked by for the 2008 Dodge Ram 3500
if you spray some ether around the engine while its running you should be able to find the vac leak 600 miles is a long drive for just a service I would find some one closer