Milk Cooling Tank

My truck has been vandalized a few days ago and I had to drop the gas tank and clean it (sugar and milk curdled in the tank) and it ran fine after that, I have never set truck, firstly, on the day and the next top radiator hose blows apart and I replace it, fill the radiator with antifreeze and water until it cannot take more, he joined and roll car a few miles .. it does not heat all over, but I park for about 20 minutes and go back outside to drive again, overheating in a matter of 5 minutes!. if I pull over and decide to do something stupid. I unscrew the radiator cap and let the steam make, thinking it might just have way to much pressure, the engine instantly cools down and im able to drive home, I noticed on the way back, the temperature began to be a little high again. What could be the problem? by the way the radiator cap is in the middle of the pipe above and not attached to the radiator itself.

Try changing the thermostat.