Originally Posted by sylver91
You might have leaked some over time, check for any leaks. Getting a colling system pressurizing pump is an easy way to find any. Also try removing the lower rad hose and see what comes out.
I don't think any leaked out, because I was running the truck a lot in 100 degree weather, and didn't experience any overheating issues. Also my resevoir was at the correct level the whole time too.