I recently changed the antifreeze and back flushed the radiator/heater core etc.
The radiator specs were 7.2 qts. So, I added 4 qts antifreeze and topped off with water. I drove the truck for a few miles, and then topped off again with water. I drove a few more miles and everything seemed ok. Once the engine cooled off, I checked the antifreeze levels and I have roughly a 50/50 coolant to water. More than maximum protection!
Will this higher concentration of antifreeze cause any problems?