Yes it’s PS fluid. Remove the return hose from the brake booster and install a length of hose from the booster into a bucket/catch can whatever. Make sure your pump is full. Run the truck with the wheels off the ground and turn the wheel left and right. Just a little not full lock. Also pump the brakes. Keep doing this till you get clean fluid out of the hose. ALWAYS keep checking the pump and keep full. Don’t let it run empty.
I recently replaced all my power steering lines and reservoir on my truck like other people said tape them up when installing. I pulled intercooler tube off mine for more room and replaced all the lines while I was in there. To the gear box and everything. If you do pull the tube off to get in there and you live where they salt roads might be a good idea to get a new clamp as mine broke where it connects to the boot cause it was a bit rusted up.
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Exactly what they stated.
Pay attention to how the one line attaches to the back of the pump. You'll need to route it the same to keep thing from rubbing together (chaffing). I failed to mention to remove the intercooler tube to gain access to the top of the steering box. Make sure you can start the line nuts by hand with a good thread engagement otherwise you could cross thread.
One last thing (sorry) make sure you account for the old O-rings. A small hooked pick tool makes it easy to recover from the ports. Use a dab of clean PS fluid to lube the new ones prior to instal and don't over tighten the nuts. They should be tight but not to the point of crushing the said O-ring. Prior to buttoning up the job, inspect any potential chaffing points and correct to include the intercooler tube. That tube is thin aluminum and will rub through fairly quickly.
Incidentally, my OEM PS lines lasted 15 years or 95K miles.