OK , looking for some idears.... This is the third gas tank i have replaced in my 96 80 in eighteen months. The 3 tanks have gotten holes/cracks in the exact same spot, on the top of the tank near the front. you can see the leak whenn tank is installed; there is no contact here. a crack about an inch long occurs where the tank is molded to accept the parking brke cable routing. The first time I thought I crushed it wheelin, but saw no evidence, replac3d with new tank from Toy, could not find junkyard tank not crushed. the second time I was stumped, thought maybe big stick got jammed wheelin, knew did not highcenter, new tank lasted 6 months, uncrushed junkyard tank with portapower and put it in. less than six months, junkyard tank is leaking. Toy has warranteed new tank with crack. I pull junk tank yesterday to find whole top of tank is crushed in, pump/sending unit tower is bent like 30 degrees. Now i have a new tank, but am hesitant to even start the truck. all tanks have installed easily with stock straps. THE Question: why is this happening? it seems as if there is some severe suction being created inside the tank. I understand this is a pressurized system. I have replaced the fuel filter about 4 months ago, not fun. Could i need a new gas cap? Any thoughts?