This is starting to really **** me off.
I've replace the PS pump with a new one trying to fix it. I've repeatedly replaced the rubber o-rings because they get chewed up at times. The hi pressure line is new.
No matter what it blows fluid out of the back of the hose where it connects to the PS pump.
The rubber o-rings is compressing, you can see it is smashed if I take it off later, and I keep using new ones.
The steal hose has no front to back play when the nut is tightened down and if you turn the steal hose when it's tight you can tell it turns hard because it's turning against the compressed rubber o-ring.
Yet no matter what it blows fluid out the back. I don't mean drip drip, I mean sprays in to the header and catches on fire!
PS works for about 3 mins until the fluid drains.
I disconnected the return hose and it had fluid coming out.
Also the PS works until the pump goes dry so I have assume it's not clogged.

 

I'll share my thoughts even though you might not like them.
I believe the new hose assembly may have been fabricated using the existing hose which had the wrong end on it. The end on it was the type used on fuel lines.
This end has a nut, a shoulder and an o-ring.
The correct end should have an o-ring trapped in a groove in the tubing below the shoulder. like this:
─╨─o─

fuel line fitting:
──╨°─

(sorry for the crappy art)
You might want to see if a local parts store has a pre-made replacement hose that you can look at.

 

I've looked at the old hose that came out of the 1st pump and it looks the same as the new one.
I've looked at multipule hoses at the parts store and they look like the one I have too.

 

Sounds like the pressure regulator valve, which is the thing that the line screws into, is cracked or something.

It just unscrews. Get another one at the junkyard.

 

You should NOT be able to turn the hose once it's tightened down. Something's whacky.

Not sure what year your car is but if it's got the later double-flare style hose fittings (as opposed to earlier 38* single flare fittings) I'm not sure the O-ring does much. The seal seems to come from the same place it always has- the metal-to-metal compression that happens when you tighten the nut down against the "shoulder" of the flare.

 

you can't turn it easy. But I mean with a 90* line coming out of it I can of course grab it and force it.