how to know wI have 98,414 mile on the subaru and was having it checked out for

With the high miles, it would be a good idea to do the belt and pump as a maintenance item more than a repair. If the bely breaks, it could cause severe engine damage, especially driving at highway speeds. And of course, Murphy's Law will have it break at night, in the pouring rain. The power steering pump is questionable unless there is a constant whining and you have to add fluid to it constantly. At speeds over 20 mph, the power steering is bypassed via internal relief valves.