power steering whine/ hyd assist issues

[josh86k10]

I just installed hyd assist, which works great until the truck gets warm... then it works somewhat. The setup I bought was for an older truck (inverted flare lines, got it off another forum) so I swapped pumps when I did the swap. Silent operation and good power until the fluid gets warm, then the power drops and it whines at any RPM over 2000ish. Do I need to try to bleed it some more? Or did I get a bad pump? It seems like it would whine all the time if it was a bleeding issue, cold or not. Also I bought a pump for a 78 to put on my 86. 78 shows 2 pumps (one with one stud hole, one with 2 stud holes). My 86 has only one stud, the local parts houses don't stock the one hole pump like I got 200 miles away so would it hurt anything to just stick a bolt in the extra hole in the one that they do have when I trade this one out?

 

[Zeus33rd]

Not really much that can go wrong with a pump, if it's new I wouldn't worry too much about it. (of course bad parts straight out of the box are possible) Your fluid is getting too hot. Anything hydraulic will cease to work correctly if the fluid gets too hot. Add a cooler and I bet the problem goes away. A small transmission cooler would work. Plumb it into the low pressure/return circuit. A filter is a good idea too.