possible bad vaccume pump??
i was driving my truck around today 96 350 with a 7.3 and i heard what i thought was an exhaust leak. got to work and popped the hood and could not find any sign of a leak no carbon or anything on the pipes but could still kinda hear the leak reved the motor and it got worse. I think it is coming from my vaccume pump but not sure if i unplug the vac line the sound dies down and is not as loud. anyone have this happen? I dont want to drop the money on a pump if that is not the problem it seems to build vaccume though.