Butler actually does work to make the van as reliable as their cleaning unit.
They change up the front fan to a different flex fan, trim off some of the fan shroud
Few other changes so that they are not just cooling the van motor...they are cooling everything all the way to the back of the van while we are cleaning.
I had a fan clutch go bad, and found one locally that would work to run the van, but the R&D department at Butler did not want me to run the unit without the proper TESTED fan clutch.
Because of what they have tested, we have been very fortunate to get thousands of Road Miles out of our units and thousands of Butler hours on the entire package.
One unit (currently still in use part time by a friend of ours) has over 250,000 road miles and over 11,000 Butler hours on if for more than 619,000 equivalent miles on the original motor...and still not taking any oil.
We also change out our oils every 1000-1500 road miles and change fluids in the Butlers more than suggested (500 hours suggested) so we are pretty sure our diligence to maintenance also might help here too.
And as I type this, I have one van I should be having the fluid in the transmission change and filter changed as we try to do that every year too....