Join Date: Jan 2004
Location: Saginaw, Michigan
Re: Power Steering works only at higher RPM
You say that everything is new so we should be able to dismiss that fact that your pump is old and tired and just isn't putting out flow like it used to.
There are different models of Saginaw pumps. They all look the same on the outside but different rings, rotors, and vanes inside the pump dictate how much fluid is displaced with every revolution of the pump driveshaft. It is possible that you just have a low displacement Saginaw pump that is just not putting out sufficient flow at low engine rpms that you experience at parking speeds. I would suggest checking with your source where you purchased the pump to see if they have any specs.
Also, the size of the power steering pump pulley versus the size of the crankshaft pulley can have a direct affect upon how much fluid is being pumped through the circuit. I have seen "power saving" pulleys that cause the pump to spin too slowly at parking situations.