changing power steering fluid?

i took my truck to the shop today for a new power steering pump. when i went to pick it up the pump was installed and problem not fixed. the mechanic said it was the steering box and that my fluid was the reason that these two componets went out. i havent ever heard of changing ps fluid, but this stuff looked terrible like engine oil overdue for an oil change really black. well the steering box is 537 $ so im not exaxctly happy. have any of you heard of changing the fluid or any input on my situation? thanks alot for any help you can provide.


Sean

What kind of trouble are you having and what year truck do you have?

i couldnt turn the steering wheel left until i started moving. it was extremely stiff steering when i was parked but only to the left i could turn right easy. my truck is a 2000 5.3. they put the steering box in and that fixed the problem.