Power Steering Pump Diagnosis

[GMC1970]

I have a 1970 gmc c2500 with a 350. I swapped out the steering box, power steering pump, and pump lines for some used parts that I thought were good. It seems as though the pump is dead. I have two questions, is it possible to swap the high pressure line with the low pressure line by accident? If your facing the driver side wheel and looking at the steering box, my high pressure line is furthest from you, and the low pressure is closest. I also realized I forgot to install the pressure release valve which I will install to see if it fixes the problem, but would that give me no power at all, or is my pump just bad?

[GMC1970]

here are some pictures, The new steering box is also leaking in that last pic, but no where else.

[mooseboy84]

If I am not mistaken (which I very well may be) arent the diameter of the line fittings two different sizes?

You should put it on jacks, and rotate the wheels left/right to full lock out about 20-30 times slowly with the reservoir full, then start it and do the same.

I bought a used PS pump/gearbox that had been sitting on a shelf for 10 years. Started right up and worked. Is yours completely dead? It should squeel like crazy when you first start it and it purges air out.

[Heated_Snail]

Mooseboy, you are correct. I just got done replacing my steering box last week and the fittings are two different sizes. High pressure used a 11/16 and return line used a 5/8.

[GMC1970]

Thanks for the replies! I see that makes sense about the different sizes. It is not making any noise at all. I had the pitman arm disconnected at first, and filled the reservoir and turned the wheel about three times lock to lock. Also after I installed the pitman arm I drove it around the block (with zero power from the pump). It took about 3/4's of a quart to fill it up is that about right? I'll try the pressure release valve tonight but it seems like I would at least get some kind of noise or something out of the pump even without it.