When I recently bought my '75 the power steering was empty and it didn't work (probably like this for a while given the overall disrepair of the vehicle). I put some fluid in and it threw it all over the tire. I then rebuilt the control valve and reassmbled everything yesterday. I think that I got it balanced fairly well.

My problem is that when making large movements of the wheel, the movement is jittery and it makes quite a bit of noise. I first assumed the jittering was just air and it has lessened somewhat but still there. However, that noise is always there while turning. The noise is similar to what you hear when you reach the end of the turning limit and keep pressure on the wheel. I hear this noise throughout the turning assist and I feel pretty confident it is coming from the pump.

I rebuilt the Pump just to be safe when I did the valve. The inside of the cylinder walls were wavy. I don't know if this is normal or not. The vanes didn't show any unusual wear.

I am wondering if this problem I am having is because the pump is not putting out enough pressure or even pressure. It was run dry for some period of time.

When I first started the car with the new control valve installed, it yanked the steering to the right pretty hard, but very jittery, so I assumed the pump was relatively strong.

I did not rebuild the steering cylinder, but it doesn't seem to leak.

Any ideas here. I thought I would ask before going out and buying a pump. Could this be the cylinder?

Thanks

 

You mention that the pump was run "dry." That is typically death for the internal parts of the pump. Continuous lubrication is critical. (That is one reason why I suggest that people use genuine GM power steering fluid. It was specifically formulated for lubrication of the Saginaw pump parts.)

You mention "waves". Are you refering to the the surface of the cam ring inside the pump? There is a special machining process that results in a very smooth surface for the pump vanes to slide against. Yet for lubrication you could see wavey lines in the surface condition. The thing you don't want is chatter or noticeable wearing of the cam surface from the pump vanes.

When you had the pump apart, did you look at the condition of the surface finish of the plates that enclosed the cam ring? If those plates are scored from rotation of the rotor and/or pump vanes, you will have a noisy pump.

I think that you need a new pump.

When you install new parts, be sure to try and get as much air as possible out of your power steering system BEFORE starting the engine.

Jim

 

Jim,

Thanks for the detail here. The control valve was leaking, so I assume the prior owner had run it dry for some time.

When I had the pump apart, the outer surface that the vanes run against was very wavy (not perfectly round). THis seemed strange, but I figured maybe it was something special. As I apply your guidance, it makes sense that the waves in the cylinder would cause pulses in the fluid flow and ultimately the jerkiness of the operation.

I will buy a new pump and try again.

THanks for your support here.

BTW, your papers on the steering components are fabulous and very helpfull. I now realize that you probably have one for the pump and should have read it.

 

Wanted to post a follow-up on this issue. I replaced the pump with a rebuilt unit and also rebuilt the steering cylinder. It is working perfectly now. Thanks Jim for the assistance and advice.

The last step in the front end restoration is a steering box rebuild. The kit showed up from Gary today and this will be my next project. I'd love to replace the idler arm, but will need to pull the header.