5000 hours is a nice dream but some Case owners have reported getting as little as 800 hours out of a replacement pump and he was not talking about this pump.
There are many factors that can affect the life of a pump but the lack of clean oil is a major contributor to early pump failure.
Case has used pumps from Barnes, Parker, Cessna and at least 5 other brands. We have no idea what the max PSI rating was for any of those pumps. Even when using a tiller, the pump pressures will be commensurate with the difficulty the tiller encounters.
If you are preparing a large garden in virgin ground, then it is wise to open the soil with a ten or twelve inch single furrow turning plow, followed by a disc harrow, followed by bi-directional or tri-directional roto tilling. By the time you get around to using the tiller, the ground is relatively easy for the tiller to turn soil into the consistency of flour and therefore the pressures don't get all that high.