Ive seen a similar Coolant tank on Amazon of all places. looks like the same unit as the one linked above, ive been waiting to see if the tubular style that dali used to make and sell will be re-manufactured in another thread.
I contacted Rev9 and asked about these fittings. They sent me this link to some fittings on Amazon that I am assuming is what they use. The description states a 'maximum working temp' of 140 F. I actually can't find any of these push-to-connect fittings anywhere rated for higher temps. I thought coolant got to 200 + F. Since these are on the exterior of the reservoir though, would they be ok to use for this application?https://www.amazon.com/CEKER-Connect-Fittings-Connectors-Pneumatic/dp/B07W6PW9V3/?th=1