1st off, congrats on your piece of heavy yellow iron. Internationals have a good reputation, and that is one big beast you picked up with some good power in it.
I am a heavy equipment operator but have never used one of the International dozers. So can't give you any specific advice.
This might be the best maintenance video for your type of machine, though placement etc might be slightly different on your machine. Do you have a manual?
I had to watch and do a lot of these for different equipment when I went to heavy equipment school. These preuse checks are a very important habit to get into. While they can seem pointless, catching a leak or low fluid can save you from a large bill to get your machine fixed.
If you could only watch one video, I would recommend this one.
Here is another, good for cross reference to see different versions
Sadly it seems most heavy equipment videos of older machines are just people tooling around showing what project they are working on, or quick demos for stuff on sale, and some showing a bit of fixing broken stuff. The fixing videos however are spotty and don't cover all the problems nor do they typically really show how it is done.
