Having intermittant minor overheat problems on 87 mond3.2 cab, but were manageable. Vehicle was new to me in 2010; only had latest service records showing coolant flush in 2008, fluid seemed clean and without sediment or rust. 88,000 miles on the beast. A leaking lower radiator tank seam finally made me pull the radiator to get repaired. Am I glad I finally did! Wow is that thing clogged internally! Eyeballing through the top opening showed white crystals at the openings: flushing with garden hose prior to transport showed only a poor stream, quite delayed, much less flow than the open garden hose provided with some sandlike stuff washing out. Plus the unit is a lot heavier than it looks, probably has 20 pounds of gook in it. Even if the seam wasn't leaking, I doubt you'd be able to dissolve or flush that much stuff out without some kick@ss industrial solvents or muriatic acid. The Message? To anyone with overheating, if the fans work and the system's air is bled out, its the radiator and it's plugged. Pull it and have it repaired.