1955 Power Steering Pump/Box issues

[Jeff Rosansky CLC #28373]

Greetings
My power steering pump gets VERY hot very quickly.  And I have no power steering.

A little background.  1955 that had been sitting for at least 20 years.  Replaced the old lines and bled the system.  Power steering pump got very hot, to the point where oil was starting to burn off the outside, and I had no power assist.  The pulley didn’t turn all that well so I just thought the heat was because the bearings were shot. Did a rebuild using the expensive kit which included both bearings and the oil seal.  Put it back on, bled and ran it.  It did not get hot but I still did not have power assist.  I don’t have a gauge so I just cracked the lines.  There was pressure, but nowhere near 700-900 pounds.  After some research on this forum (I don’t know how I could do anything without the help of the experts on here) I found that the fancy kit supplied the wrong o-ring.  A couple guys on here came to my rescue and I was able to determine the problem and get the correct o-ring………. Have I lost you yet? Put the pump back on and still no assist.  This time, however, the pump gets quite hot very fast again.  I cracked the lines and fluid shot everywhere so there is significantly more pressure than before I replaced the o-ring.  When the engine is running, I see fluid returning thru the front hole in the tank-just running and not trying to turn the wheels.  With the engine off, wheels off the ground, and I turn the wheels very quickly   it seems that fluid comes up thru both the front and center holes.  When I turn the wheels more slowly, I see the fluid sucking and being returned in unison in both holes.
My little brain is thinking that the first run, and the current run has the pump making pressure but it isn’t able to go anywhere.  The pressure is causing the pump to get hot and the power assist portion of the steering box is frozen? Does that sound logical.  If so, any suggestions on how to free it up?  I don't want to pull the box at this point.  If it is dead then I will just live without power steering. 

Also, In the manual I see a filler plug on the steering box.  I didn’t see any reference to it but is the box filled with another type of fluid that I should check? 
Sorry to be longwinded, but I wanted to give as much information as possible.
Thanks all
Jeff

[Mike Josephic CLC #3877]

I believe your issue is not with the hydraulics of the system, but with
the steering gear side.  Read on:

The 1954-55 Caddies had a rather unusual power steering pump.  It
was a "hybrid" affair.  One side was hydraulic (with power steering fluid)
the other was old style gears, same as the manual unit.  That side used
steering gear lube (GM spec. #4673M) which was 90 weight MP (multipurpose
gear lubricant). Open that plug and check the level.  It should be up to the
opening where the plug screws in.

SAE 90 W or 85W-90 MP would work fine.  It can be found in any good auto
parts store as it is used also in the rear differential of many vehicles.

Mike

[J. Gomez]

Jeff,

I would take a wild guess your issue is with the hydraulic portion at the steering box as you have speculated on your assessment.

There is a high pressure built up at the pump and there is no proper circulation back from the steering box on the return line, which could be the main issue the pump gets hot.

Anything can go wrong in that section a frozen valve or a power piston, so unfortunately you would need to take the steering box out to check the hydraulic side. 

Good luck..!

[Jeff Rosansky CLC #28373]

Well, that is what I was afraid of.
I will check the box oil. For now, I will just pull the belt on the pump and drive it manually. Who knows, maybe just driving it will free it up?
Jeff