Hey no problem, even some of the surplus companies have the radiators for under 100. I think the model that I need is one from a Bobcat.
I should have taken pictures of the work we did, the valves I got from eBay and tested them at 1000 psi (they are rated for 2000 psi).
I was thinking about if you don't have a radiator, using a radiator and an electric fan that can be mounted off the apu would work so when you are idling, the fan pulls air through the APU.
Again so much can be done, mainly because out of the 10 or so different APUs I have looked at, not one of them has a custom engine built by the APU company.
Mine has almost 8000 hours on it. I just got the water pump replaced but now I have a small oil leak. I hate to see what that is going to cost to replace all those seals.
I would REALLY like to find a way to replace it. Darn things are just so expensive. TOO expensive if you as me. I can buy a pretty good used car for what these things cost.