I need some help with the power steering on my Plymouth. Car has a 318 Poly with the Federal/Thompson type power steering pump. These pumps are hard to find and I am running a re manufactured one that took forever to find. The issue is at low RPM or idle the power steering doesn't work, but at higher RPM cruising speed it will. It did this once before and I took the cap off and turned it to brake in both directions, it gurgled and started working again. I assumed it being new it had gotten some air in it. However a couple hundred miles later it did it again, this go around the previous fix didn't work. I took it off today, blew out all the lines, drained the fluid, and cleaned the trap filter thing on the return line but had no success after re-installing it. Anybody have any suggestions on what to do? Is the pump shot?
Most modern pumps run in the 1000 to 1200 psi range . You might want to find specs on your actual pump. I would find a 0 to 3000 psi gauge and remove the pressure line are the gear and adapt the gauge to fit the line. This will dead head the pump and tell you what preasure it is capable of. If the pressure stays low you know you have a pump problem If not you have a gear problem.
I believe that Federal pumps have a pressure relief valve that opens at highway speed and diverts the pressure back into the reservoir, because less pressure is need for steering at that time. If the valve is stuck open you might not have enough pressure at lower rpm .
Moose, Thanks for that info. I figured it had something that did that function or it would blow hoses or the steering would be uncontrollably light. You have a suggestion as to how to get it unstuck?
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