Excellent article called "Pressurized Cooling System Considerations". There is a link on the D2 forum, or go to extinctmotorsports.com and search the engineer's blog. It gives the pros and cons of pressurized vs unpressurized. One point to keep in mind is that lower pressure means lower boiling point, and that can impact operation at high elevations where atmospheric pressure is lower. That is not an issue for my trucks because I don't go that high, but needs to be accounted for in places like Colorado.

 

Welp, that was an interesting rabbit hole for the last 45 minutes or so.

 

Hey JohnZo,

Thanks for the article. It did make for a very interesting read. I will try this method and discovery the results with my rig. I will not be in any high elevations where atmospheric pressure.

Here is a direct link to the article JohnZo mentioned for those interested.
https://extinctmotorsports.com/the-e...s-10-min-read/

 

For me the aluminum tank was about "bullet proofing" the D1. I do a lot of off-roading, a fair amount in Utah and Colorado so at higher altitudes than I have here in Texas.
I off-road with my wife and we do a lot of very remote trails. Really don't want to break down with her because of something I could have prevented.

I will say I don't think 12psi should crack the plastic expansion tank or pop a head gasket. Makes me now question is my cap working. My plastic tank was only a year or so old and it started to crack.
I watch my UltraGauge like a hawk. On the trails, I turn the heater on when it hits 199-201F (I'm working on relaxing on this - LOL). It's not about boiling points as much
as it's about "cooking" the gaskets and such.

I'm running a FlowKooler H2O pump, AB metal tank RAD, HD fan clutch, 180 t-stat and now the aluminum expansion tank.

 

One of the nice things about the Ultragauge is that you can set the alarm for a coolant temperature and you don’t need to watch it like a hawk. (Though it’s still good to keep an eye on it).

 

Good tip Harvlr,
I should set an alarm because I also watch the coolant temp gauge like a hawk.
Since 2016 watching the UltraGuage temp gauge has simply become second nature anytime I am in truck.

 

Not sure where 12 psi figure popped up. Spec is 16 psi. Have some members procured 12 psi caps? Are there other ratings available?

 

Rovers North states that stock is a 15psi cap. https://www.roversnorth.com/parts/nt...on_tank_15_psi

I've been running this generic clear'ish tank from Amazon that comes with a 16psi cap with no issues.
I bought the first one in 2019 which failed in just over 4 years, so I bought the same one in 2023.

 

I would hope to get way more than 4 years out of such a critical part.

 

I got about a year, that’s why I switched to aluminum