Hello new guy with a problem

[Redlazer]

I was walking by my truck about 5 mins ago and heard a vibration coming from under the hood. I opened the hood and it was the vacuum pump vibrating. Anyone knows what the problem is? I unhooked it and it stopped vibrating. Is the pump bad? Also what in the world does it do?

[jshalala]

Vacuum pump controls auto front hubs if you have them, also controls your climate control direction, ie switching between defrost, floor, vent etc. I'm sure it does other things too, thats all I could think of

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[NCHornet]

It will run for awhile when first started. Check your connections at the back of each front hub, assuming you have a 4x4. Another area that gets kicked loose is in the pass foot well up above. When you have a vacuum leak you will only have airflow out of your defrost.