My son has a Dodge with Cummins engine.The truck was from a construction company and the truck was not keep up with. Now the power steering fluid is foamy up and drain all over the driveway. He keeps filling the pump up so I don’t think the pump is damaged…any ideas??
You have a leak on the suction side of the pump and/or a restriction in suction (low pressure) hose from the reservoir to the pump (unless the reservoir is a part of the pump).
Check that there in not a plugged filter screen inside the reservoir tank…Many (most) fluid reservoirs have a filter screen protecting the pump inlet hose…If that screen plugs up, the pump will starve for fluid, make noise and foam what little fluid it can pull through the plugged screen…
Is the return line really hot. If it is, the system pressure is too high. The bypass valve in the steering gear box is not working. If its not hot, then it’s a suction side restriction.