vacuum leak

[peyton4x4]

Well recently in driving I've heard a hissing noise upon hitting the gas, so today I opened the hood. I hear a hiss from somewhere between the exhaust manifold and the power steering fluid holder. When I listen it hisses and then stops for a second. When it hisses the engine rpms drop slightly and sounds as if it wants to stall and then the hiss stops and a second later will start back up. I can't find the leak much less do I know what to look for. any help is appreciated. Thanks

 

[Keepinitoldskool]

What year model truck? Some of these had pressure valves on the bottom of the power steering pump it could be the cause.

 

[peyton4x4]

98 k1500 with the 5.7 vortec

 

[peyton4x4]

I just checked for a leak in the exhaust manifold and couldn't find anything. Definitely sounds to be coming from around the power steering pump, although I didn't see any vacuum lines

 

[Keepinitoldskool]

There isnt. There is a high pressure valve on one of the lines comin from the pump. You may be hearing it malfunctioning and hissing as fluid rushes through it. Thats if yours even has one.

 

[peyton4x4]

When I hit the gas from a stop, I can hear the noise very clearly in the cab. I'm at a loss.

 

[skylark]

Take the belt off and fire it up for a minute. This will eliminate any spinning accessories. Then grab out the can of carburetor cleaner and start spraying all the vacuum lines.

 

[peyton4x4]

Also, the rubber grommet on the pcv valve connectino to the intake is kind of cracked
Should this be replaced?