Coolant Pressure relief???

[XWrench3]

ok, yesterday i installed a new set of spark plugs in my (3.7L) Liberty, and of course you have to remove the coolant bottle to get to the last 2 on the passenger side. no big deal, 2 nuts and 2 clamps. but while i had it off, it occurred to me that there is no place for pressure to go if it gets higher than the 18 pound (YIKES!!!) cap. there is a hose like there would be on every other vehicle i have ever seen, but in this case, it goes right back into the bottom of the bottle. what gives? unless the coolant bottle is designed to fail after enough heat and pressure builds (and SOMETHING DEFINITLY WILL!), i don't see a way to vent pressure in a very high overheat condition!

 

[LibertyTC]

I just drop the tank down, & move it off to the left a bit, never had to remove hoses on recovery tank to swap out the rear 2 plugs.
Never overheated my KJ. Similar to a normal rad cap it will vent out of the cap if it gets too hot, after that IDK...

 

[tommudd]

Expansion tank, if it gets too hot it flows back up into the tank
You notice you do not fill it plum full, and one of the reasons is just that, if it gets hot , antifreeze will boil back into it

Over thinking many things that are not and should not be an issue

 

[LibertyTC]

BTW Mopar cap should be rated at 16 Psi..NOT 18.

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[XWrench3]

it might be 16, i seldom wear my glasses when working on cars. so 16 and 18 look (to my old eyes) pretty much the same.