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This past winter I replaced everything on the power steering system on my 79. After the new parts were installed the steering wheel would not return to center after turning a corner. My GM shop manual refered to the spool in the control valve as the problem.
I replaced the control valve yesterday morning. After installing the new control valve I now have a new problem. Once the engine is started I get a loud squeling noise from the power steering pump. After inspecting things it appear the noise is from the belt on the pulley. I noticed the pump is binding as if to have hydro lock and causing the belt to slip.
The pump will spin freely with the belt removed. Once it was so bad it caused the pulley to almost walk off the shaft of the pump. What could be wrong in a control valve to cause so much resisantance in the pump...do I need to replace the control valve again?
Cant balance the valve without running the car and the pump seems to be binding. Didnt have this problem untill this control vavle was installed.
The hoses are hooked upper cylinder to lower control port and lower cylinder to upper control port. Just as it was undid before the valve was removed...the piston doesnt move at all now.
From your description is sure sounds as if you have complete blockage of power steering fluid flow which would cause the pump to be dead headed. Since you only changed the control valve and nothing else, it certainly would seem that the problem is with the new valve. Maybe someone assembled it incorrectly (although you would hope that the company that manufactured it would have tested it for function.)
You might inspect the brass seats in the control valve ports. It is remotely possible that overtightening the hoses into the ports could have distorted the brass seat(s) causing a blockage of flow.
I am a bit concerned that you could have ruined the pump. It doesn't take long with the pump dead headed to build up very high steering fluid temperatures that could damage parts inside the pump.
Also, that is a very high interference fit between the pulley and the pump driveshaft. Even with the pump dead headed, the pulley should never "walk off" the driveshaft.
Jim
I just rebuild my controll valve last month and when I started the engine the wheels turned all the way to the right before I could balance it. In the process of balancing, I turned the adjustment nut the wrong way and the belt squealed. Perhaps the valve is adjusted so far off that it is the same as holding the stearing wheel all the way to one side. Try loosening the belt so it slips and do a valve balancing proceedure.
Thanks Waterman, tried your idea tonight and it appeared to have worked. I still plan on changing out the power steering pump because its under warrenty. Thanks for the help-...