Just bought a new Frontier. I pulled the cap off the reservoir and it had a LOT of pressure when it unsealed. Didn’t expect that but the reservoir cap looks like a regular radiator cap. Then I took the radiator cap off, no pressure, but it did not look like a radiator cap, it didn’t have the pressure relief valve built in, it was just to seal the radiator and nothing else.
First thing I though was that the caps got mixed up at the factory or dealership, but the label on top of the radiator cap said “Do not fit on overflow tank.”
The overflow tank was at the proper level but the top tank of the radiator was almost dry. Something doesn’t seem right.