Plastic for cooling sucks.

I worked on medium and heavy trucks (class 7&8) for 40 years at a municipal garage. International and Freightliner had plastic coolant tanks. I might have replaced one International in that time. Freightliner's lasted about 3 years and would get pin holes in them. The Peterbilts had metal tanks and never leaked. The plastic/aluminum radiators are a toss up. Some last and some don't. FYI a Freightliner radiator 5 years ago was $2300.