C2 power steering slop in control valve?

[Timothy B.]

I discovered tonight as I continue to troubleshoot what I described as "squirrelly steering" (see the link to the earlier post with details), that there is noticeable and uneven play in the PS control valve. Are there any experts out there on C2 Corvette PS and in particular the control valves that can fill me in on what is normal?

I noticed that as I carefully rotate the steering wheel left and right and watch the left front tire (wheels off the ground and reaching through the open door with my arm), that I can turn the wheel a few degrees left without the tire responding. When I try the same to the right the tire responds much quicker. What I discovered is that there is significant and un-even (left to right) play between the PS control valve pitman arm stud and the control valve body and therefore the relay rod. Since I have a long reach, I was able to place my fingers on the interface of the stud to the control valve with my other hand on the steering wheel. As I turn the wheel, I can feel that the studs moves a certain distance before it feels like it hits a stop and then moves the relay rod (and therefore the wheels). There is significantly more "freeplay" to the left than to the right.

In order for the valve to sense load and provide power assist there must be motion, so I understand that there should be some. Question is, how much motion is normal and at what force?

My PS valve (along with the PS cylinder and pump and hoses) were all rebuilt units from Chicago Corvette a couple of years ago. Hopefully they supplied me a valve with the 55 /b spring in it, buy maybe not. The adjustment cap on the valve has a "C" stamped on it, but since it is rebuilt there is no telling what is inside. The valve has no leakage and otherwise works fine.




Earlier topic "Squirrelly steering"

[Terry F.]

Re: C2 power steering slop in control valve?

I remember adjusting my control valve a long time ago after I rebuilt it. I remember hanging the front end up in the air and adjusting the valve so that it had no pull to either side. The adjustment is under the control valve cap. You may already know all this stuff.

The other thing that I recall when rebuilding my power steering pump was that the overhaul manual showed a flow restrictor for the corvette. The description said, corvette only. I have always wondered what the effect of that restrictor would have on the feel of steering if it were missing.

I would not get too worried about the flow control valve unless it was noticably easier to turn the steering wheel to one side or the other.

If I think of anything else, I will let you know. Terry

[Wayne W.]

Re: C2 power steering slop in control valve?

I would do the centering adjustments to the valve and recheck the movement. Actually there is a lot of movement there with the engine off. Many people get concerned about nothing when they see this. With the system pressured up that play goes away. You should check for play and operation with the engine running and the wheels on the ground.

[Jack H.]

Re: C2 power steering slop in control valve?

How did you initially set the over-center adjustment when you installed the system? You know you CAN'T just take parts out of the box and bolt them in place without making the over-center adjustment as the shop manual explains....

[Timothy B.]

Re: C2 power steering slop in control valve?

Well, Wayne was correct. Apparently it is normal for there to be quite a bit of play in the control valve with the engine not running. With pressure on the system the play disappears best I can tell. I can now see response in the wheel with only slight motion of the steering wheel. If I grab the control valve again like I did before but this time with the engine running, and rock the steering wheel, there is still some small amount of play but not much.

I followed the instructions when the valve was installed last year on centering adjustment.

I drove around the block with the PS belt disconnected just to see what the centering feel felt like without PS, and boy was THAT fun. Manual steering with the tie rods in the PS holes equals really high effort! Also, that play I noticed with the engine off was VERY apparent. I could turn the wheel probably 5-10 degrees each direction without ANY reaction by the front wheels. Talk about free play! Apparently that is the design of the control valve as Wayne pointed out.

I'm starting to eliminate causes of my original complaint, leaving things like toe-in, the wrong PS control valve spring, etc.

[Timothy B.]

Re: C2 power steering slop in control valve?

And of course I could have messed up the gear box rebuild since it was the first time I had done that...

[Timothy B.]

Re: C2 power steering slop in control valve?

Tim,

I don't know if this will help but I overhauled the valve on my 63 and followed the 63 corvette shop manual. If my memory is correct there is a adjustment of the ball stud and seat and this adjustment can be tightened up but you have to take the valve apart. Read the 63 shop manual before you try this, I would think that if you purchased a rebuilt valve this adjustment would be fine but you never know now a days. Outside of that if all the linkage is good I would look at the steering box as Duke suggested.