Okay I have been having trouble with loosing coolant. when the truck is under strain i.e climbing hills, or getting into the throttle, I will spring a leak. the coolant gets in the driver side wheel well, and all underneath the truck, but nothing comes out of the overflow/burp bottle. Haven't been able to pinpoint were its leaking from. took it and had the system checked with a pressure test and no leaks were found. Does anybody have any clue to what may be going on?