Help with hydraulic issue on ASV 120

[Ironman]

A neighbour had the same thing going on with a Cat track loader he had them rebuild. After it warmed up it started to turn to the left after 10 ft and kept slowly turn, and power was down.
After much argument, and laptops being waved around, the owner went over the heads of the rebuild shop and hire a Cat tech to have a look.

The problem was the engine rpm was set 250 rpm too low. He tapped a couple of keys and the problem was fixed.