Chris, Want to pick your brain for a minute. My radiator on my TM shows signs of leaking at the very top. I can visually see the trail from the top to the bottom. The radiator cap is in the center. Not leaking from there but somewhere from the top, closer to the side. I have pressured tested it and can not see any signs of leakage. That was done when the radiator was cool. Can you pressure test under hot coolant? Would this show me where it is leaking? What about a dye in the coolant, is this possible? the level in the radiator is down about 1" from the top, so i believe it is leaking somewhere above this level. Have replaced the cap. would like your imput. thanks aaron