Power Steering Overheating?

Well, on my way up to a trail my XJ started whining real bad and the power steering began bubbling an shooting out. I let it cool and took it back home. Last night I followed the procedures that PSC gives for bleeding it's system.
Everything tested out fine so I tried taking it back up to Clear Creek again.
Was good until we reached the trail from Denver. The noise began again and the pump was bubbling and screaming. The fluid is milky again..
I replaced the pump over this past summer.
Is this a pump issue? Should I replace it again?

Did you bleed it out after you replaced the pump?

Side note: There are some vehicles that come factory with a power steering cooler from the factory.

We didn't follow the PSC procedure, but we filled it until it came out of the return line before. We bled it properly last night, could this have been ruined from the initial install?

I could be wrong but I am sure it had something to do with it.
Something had to cause the fluid to heat up, could have been an air bubble.
Is there a warranty on the pump? If it were me I would replace it, bleed the system good, and call it a day.
In your Haynes/Chiltons/FSM there are instructions on how to do it right.
HTH

Yes, there is a warranty on this. I'm planning on getting it replaced. This pump is still churning air bubbles. Hopefully some Colorado guys can help me out. Have a few things that need to be done.

Surprisingly running a power steering out of fluid rarely causes problems. Moisture or bleeding are the most common problems. I'm about an hour north of you. If you could get it up here I can help take a look at it. I have a rebuilt more steering gears than probably anybody on this forum.

It seems to be decent at higher speeds, but overheats quicker at lower speeds. I didn't have any issues driving from Chicago. Does the elevation play a part at all? I have no idea, just throwing out possibilities.

I pulled the factory PS cooler from an F350 from my local you pull and pay. Think it cost $12 or so... Personally, I always run a cooler on the PS return line.

Altitude does play a part in cooling as the air density is less which lessens the ability to transfer heat. You loose hp as well up here.

If you can get your rig up to old_man it will be worth your time. Has all of his stuff in the proverbial sock.