Stock p/s control valve adjustments

[chevyman1957]

I've got a 57 belair w/stock p/s. I rebuilt the control valve, and after re-installing, I could not get the steering to stay in adjustment. It would seem to work okay until the system got warmed up, then it would either kick back right, so I adjusted 1/4 turn at a time until it seemed ok. Then after going lock to lock a few times, it would start kicking back the other way. I would adjust some more until it seemed ok. It would also sometimes just go back and forth on it's own until I either shut off the engine or tightened the adjustment until it stopped. I kitted the valve again, thinking I messed up somewhere. I did notice on one of the piston rod machined surfaces that there was some pitting. I smoothed it down with some 1500 grit wet or dry, but it still had some very minor pitting when I re-assembled it. I also tried to smooth out the inside of the housing as well. I'm still not able to keep it in adjustment, and it still sometimes wants to go back and forth on its own. It doesn't go lock to lock by itself, just about a 1/4 turn both direction, and will gradually work it's way from one side to the other. Last but not least, I also noticed that the valve and pump are getting pretty hot to the touch after trying to adjust it for 10 or 20 minutes. I've also been using Dexron/Mercon instead of p/s fluid, and have been using a later model Saginaw pump. Could that have something to do with it, or is it time I just convert over to a 605 and move on? Thanks for any input...

[Rick_L]

My recollection is that the centering procedure for the hydraulic valve requires much finer than 1/4 turn increments to get it right - it is much more sensitive than that. You are checking the system with the hydraulic cylinder disconnected and watching its movement aren't you?

I was curious about the procedure so I looked in the shop manual but couldn't find it. I also looked in my 67 shop manual because my Nova's power steering is the same type, and couldn't find it there either. Maybe where I saw it is in the instructions for the valve rebuild kit.

Hopefully the expert Jalapeno will see this and elaborate. He sells and rebuilds these components.

[Jalapeno]

Welcome to Trifive.com

There is no external adjustment to the 55-57 valve like there is with the later valve. The valve must be assembled correctly and the parts in the correct order, sounds like you got something wrong. The large plug (with the long relay rod that has what you think is the adjustment nut on the end) must be threaded all the way in, then backed off enough to insert the pin. This is critical to assembling the valve. Check the shop manual for the procedure and for the right order of parts.

That said, the turning back and forth is indicative of another issue. Look and see if you have the hoses plumbed correctly. On the pump, the pressure fitting should connect to the SMALL orifice on the valve. The clamp-on return hose should be connected to the LARGE orifice on the valve. This condition will also heat the fluid abnormally.

Also, the hoses from valve to cylinder should be parallel (they do not cross), with the cylinder ports ABOVE the shaft. It's possible to mount the cylinder upside down, and when the hoses are run parallel to an upside down cylinder it is the same as having them crossed.

[57viper]

Check your mailbox I sent an article your way, hope it helps.
Bob

[chevyman1957]

Okay, that's what I get for trusting someone else to build and install my p/s hoses. The pump hoses were reversed. This is a learn-as-you-go project for me, as the car has not been licensed since 1971, and I've just recently had the funds available to put it back together.
I do have another question, tho, for Jalapeno. After the valve is re-asembled, how much thread should be available at the end of the shaft for the nut? The first time I had a hard time compressing the valve enough to attach the nut. The second time the shaft had quite a lot of threads showing and the nut was easy to attach. When I do this again, I want to be ABSOLUTELY sure I'm doing it right.
Thanks, everyone for your help. I'll let you know how it works out....
Gary

[Jalapeno]

Gary, there is a spool spring that you are compressing in order to install the nut. The threads should not be so exposed that the nut threads on without compressing the spring somewhat. Check the assembly of the valve parts again, make sure you didn't leave out the small spacer at the end of the spool.

The hoses you need (late model pump to stock valve) are manufactured, no need to make custom hoses. The set I make includes a CNC formed pressure pipe and a clip, everything fits together and is routed around the engine neatly.

EDIT: It's possible that if your spool spring is weak (but still viable) that the relay rod threads can be exposed enough to thread on the nut without manually compressing the spring.

[chevyman1957]

Just wanted to drop a line and say thanks to all that sent in suggestions in regards to my p/s control valve problem. I've got the hoses on correctly and the control valve re-installed and everything works great. And especially thanks to 57Viper and Jalapeno for their help.
Gary

[Jalapeno]

:tu:)