The suggestion was made in another thread that owners keep a list of known issues for their coaches, so that prospective buyers can check on what they might be up against. I'll start the ball rolling with our coach. Others can chime in with their knowledge.
The hydraulic pump that runs the two radiator fans is basically a stock pump EXCEPT that Foretravel changed the shaft to a slightly longer one. That makes it a proprietary part. FOT parts department is supposed to have some in stock, and order more enough in advance that they don't run out, but that doesn't always happen. Fortunately, it is a pretty sturdy little pump, so a seal kit every 20 years or so is probably all that is needed.
The radiator fans have been replaced with newer models that require different mounting brackets, etc.
Engine air intake is behind the curbside rear duals. KenHat or Kent Speers (can't remember which) has a pretty neat improvement.