12.7 Detroit pushing coolant out of overflow

Let it cool down sounds like it’s a closed system like all the new cars. It expands and when it cools it goes back down . Wait till morning and when all the coolants gone don’t freak out it just went back

 

It’s a closed system the reason being its designed to run under pressure because as pressure rises so does cooling ability It takes longer to hit boiling point (234) or so when it’s under pressure. I hope that’s all it is. Otherwise you may have to just shoot it!!!

 

I'm not going to read through all the posts, I'm just going to ask: while you were changing all the expensive stuff, did you change the $12 cap? I've seen more overflows fixed by putting a new cap on than anything else.

 

He said he did

 

I have a cat and sometimes I get coolant out of over flow. I reckon that’s the purpose of it.
Usually will only see this if I’m parked nose forward on a very steep incline or I guess it would be a decline if my nose is pointing down hill

 

That’s what it’s for an expansion tank same as modern cars. They need extra pressure to keep boiling point down. Look at a car it has a cold level that’s lower and a hot level that’s higher up on tank.If you overfill it when cold u run a risk of it overflowing when hot . I’m pretty sure the new trucks run a higher pressure closed system as they tend to run hotter. I may be wrong I’m not a mechanic

 

I park my new car after driving it and coolant level is at high hot mark. Get up in morning and it’s at low mark . The only place it went was from overflow tank ( resivior) back to radiator/ engine