Posted by Jeff N on January 19, 19100 at 10:51:12:
In Reply to: Stiff steering at first posted by Mike on January 17, 19100 at 20:00:50:
I just changed my steering pump in my 91' and I learned it was very easy to flush out the old fluid.
First you need the truck off, then you remove the low pressure return line that connects the steering box to the pump. Take the hose and place it in a can to collect the old oil. You also might want to cap off the inlet on the pump to prevent excess oil from flowing out from the reservoir.
Next item is to turn the engine over a turn or two, WITHOUT STARTING, and this will push the old oil into the can. Pour in fresh oil in the reservoir and repeat until you see clear oil coming into the can. Reconnect the hose and fill to the proper level. Make sure you done run the pump dry. This will put air in the system and is not good.
I also learned after it was put back together with fresh oil and moving the steering wheel around a few times kicked in a bit more of the old oil. To fix this I flushed the whole system again. I noticed that the steering box still kept some of the contaminated oil after the first flush.
Also, don't mix synthetic power steering fluid with regular fluid. A mechanic told me this but I'm not sure of the reason. He recommended using regular oil because the next time someone had to fill the reservoir, chances are they would use regular oil rather than synthetic.
Hope this helps.