20 k and 2 year Indy service on truck today

[Turbo Terry]

I notice that the 2022 has more pressure when hot and you open it then my old 99 5.9 . I always had to add a bit from time to time on it, I think it’s normal

 

[Ozymandias]

You should never open a pressurized cooling system in hot state.
It can instantly boil and even damage the engine through that, taking away the coolant from internal hot surfaces by boiling.
Our engines normal operating temperature is very close to the boiling point of unpressurized water, just a tick more heat and it boils violently.

 

[Turbo Terry]

I never do and I know that as most do but on the 99 there was no pressure on the reservoir tank but on the 2022 there is even when just warm

 

[AH64ID]

I never do and I know that as most do but on the 99 there was no pressure on the reservoir tank but on the 2022 there is even when just warm

The cap on the reservoir is the pressure cap, which your 99 had two different caps (reservoir and radiator). The 22 has a sealed radiator, so opening the reservoir warm is akin to opening the radiator warm on the 99, so you are doing what you think you aren’t. Only open it cold.

 

[Turbo Terry]

It’s a relearning experience. Completely different truck in many ways