I have a Cat 939c track loader and the left track is dead and it will not turn left or right the loader is a hystat it also does not travel fast and the high and low speed button is inop. I am doing this for a customer he wanted me to take a look at it to see what i could do I am a truck tech mostly but have worked on 955,977,963,973 loaders never had the pleasure of working on one of these. If I could get some help without having to buy a 300.00 dollar manual I would greatly appreciate it thanks.