I always look to make sure theres not any dead fish inside the machine or stuck on the radiator, or high water stains on the inside of the sheet metal. I was at a sale one time and a dozer had dead fish inside the belly and also dead fish on the inside of the radiator at the bottom they were the little minnows, I first thought it was a joke and after looking at it a while it had been in a flood and had algea growing up under the dash and there was a waterline in the cab, not very noticable but it was there so it was totally submerged above the intake on the hood and they tried to clean it up as best they could but didn't do a very good job of it. After looking closer at the fluids and dipsticks they all had a white looking slime on them somewhere so all the fluids were full of water at one time and they tried to empty them out and flush them as best as they could but its doubtfull you'll ever get it all.
Over the years I've know of two tractors that went into ponds through the ice, a skid steer that went into a manure pit, a tractor that went into a manure lagoon, and several dozers that were submerged in ponds that were being built and all were bad news and the owners finally gave up and traded them off for someone else to fight with. I always reach inside panels that aren't normally taken off to see what I can wipe off on my hands to see whats not noticable from the outside or can't be reached with a pressure washer or steam cleaner. Just a suggestion for something not really thought of by most.
Over the years I've know of two tractors that went into ponds through the ice, a skid steer that went into a manure pit, a tractor that went into a manure lagoon, and several dozers that were submerged in ponds that were being built and all were bad news and the owners finally gave up and traded them off for someone else to fight with. I always reach inside panels that aren't normally taken off to see what I can wipe off on my hands to see whats not noticable from the outside or can't be reached with a pressure washer or steam cleaner. Just a suggestion for something not really thought of by most.