Great thread! I only wish I'd had access to the information it contains when I had my overheating problem. It started overheating (cummins ISL 400hp) pulling hills and whenever it got hot outside, I checked and cleaned the rad/cac and it was clean. Took it to Cummins NW and told them it was either the rad/cac really was plugged and I was wrong, or it was a bad fan belt, or, probably most likely, a bad fan clutch...
Anyway, they called first day and said the fan was not responding to the computer, bingo, I told them throw a clutch at it! Long story short, three days later, too late to fix it due to upcoming had to go trip, I had to take it and be careful... The worst part, they charged me over a grand to tell me that it was, indeed, the fan clutch! Anyone else ever have a bad day like that with a shop LOL!!
I've got to add to this by edit.. reason it took over 3 days was they kept telling me it needed more diagnosis time...
Question, do all freightliner chassis have the additional access under the closet? Assuming it would be under the wood floor of the closet (remove the wood?)
My unit is 2007 Sportscoach Legend Freightliner XC chassis...