You are not over filling it are you? What color is the fluid? Sometimes when the pumps get worn they wont make any noise but the fluid expands or foams
because of heat. What is the truck used for? Are you doing allot of constant turning? Just some Q's
Where I work we change out two power steering pumps and filters a month, sometimes more. Our trucks have drop axles which are lifted when backing up.
When the axle goes up the steer axle weight goes to 15,500 lbs. And if the dock is hard to back up to and the driver does not get lined up the best he can,
the steering fluid gets real hot. Every time the pump over heats a little more life goes out of it. Dry steering is the worst thing on pumps. The newer TRW
aluminum body pumps can't take much hard work. Your's should be a cast Vickers depending on engine.
Truck Shop