I had a CG&J radiator installed in 2015 after road debris took out my old one. I had researched and thought it was a good option. I contacted one of the top guys and we had multiple phone calls emails so I went ahead and pulled the trigger and ordered it and had it delivered to the Cummins shop doing the work. I thought all was good.
Another Monaco Windsor owner also had one installed. He ultimately reported to me that his started to leak and used Irontite to fix the problem.
I used the coach for one long trip in 2015 and then it pretty much as been sitting on the property we bought as I build the new house.
This year I finally got the rig ready to travel and took it on a ~5K trip. When I got home I backed it into the garage and the next day I had a leak under it, over the period of a week it continued to seep while I worked on some other stuff. Finally got a chance to put some Irontite into it which stopped the leak. I have since taken it on another ~5K trip and it seems to have stopped the leak.
But during this time I have been seeing higher transmission temps. I took the time to email my contact at CG&J to question about sizing of the transmission cooler, internal to the radiator. He simply aid they size it to about what was in the old radiator that they had used as a template. I asked him my options and he offered to sell me a separate cooler for ~$750. The other Windsor owner also says he sees slightly higher transmission temps.
I also told him about the leak and he said they do not recommend using an additive in the radiators, he said I could remove the radiator and send it to them to check. This seems like a poor business model.
So I will no longer recommend CG&J.