My 790 has the model 300 deere loader. Bought the Deere shop manual not long after the 790.
I have had to replace the hydraulic implement pump twice, my own fault, replaced the bevel and drive gear on both sides of the mfwd and two water pumps.
Original water pump missed the three year warranty by one day, second one not sure what happened. Started leaking just like the first at only 175 ish hours, Deere water pump to boot with a flushed system also. Third pump install I used a whole bottle of coolant treatment with new coolant after another flush. So far so good.
The 790 was max what i could afford new and after 13 years of being my only tractor, year 'round use sometimes hard, it got me were I am now and would do it again...
Deere dealer was real good to me, wish it was still here. Between my work back then and the tree farm, I was in there often for parts, supplies and knowledge. It changed hands and most of the original employees left after the 'buy out'. The new management of the dealer is not the same and a lot of farmers, loggers and long time customers like me took there business to different dealers.... Like the LS tractor I own now.