Any Cummins nuts out there?

I have a 98 Cummins 12v at my ranch and have been having some problems with it lately. I am not down there at the moment and the ranch-hand isn't exactly a "go to mechanic", so any help from you guys would be much appreciated.

From what he has been telling me the steering seemed to be stiffening up a considerable amount, checked and added power steering fluid and the problem still continued. Last week I sent him to go buy a new power steering pump. He replaced the old one, but the "steering problem" still continues! He just says it is very hard to turn, and now it is overheating regularly. Any ideas... replace the water pump? Are there any blueprints of a 12v? I have been having a tough time finding anything online..

I am heading out there (5 hour drive from my house) tomorrow morning to do some work before archery season opens this weekend, so if there is anything i need to get from the parts house i'll need to do it before the weekend.

Thanks in advance guys!