My Formula had a little problem the other night and we lost alot of anti-freeze from the system. I replaced the broken piece and refilled the res. Took it out tonight and it's overheating real bad. It's acting like there is no coolant in it, but the res. is full. Is it possible to have air trapped in the system or does this sound like a water pump issue? Does anyone know how to pressurize the system to push air out? I got under the sled and the heat exchangers were cold and covered in snow as if there is no hot liquid flowing through them. Any help would be greatly appreciated.