Just after I've pretty much figured out my cooling system problems on the suburban the sierra decides to act up. When I shut the truck off or when it is idling, I notice a substantial leak coming from what looks t be just behind the serpentine belt/pulleys. If it is shut off the liquid seems to run down the back of the center pulley and onto the ground. The Upper hose and thermostat look to be fine as does the bottom hose (at least what I could see of it). Any ideas why it may be leaking??? :neutral: It's a 99 old body style 5.7 vortec.