carriljc

So, I was tweaking on my steering valve (I believe that is the correct term) and somewhere along the way I lost the end "cap" that covers that adjustment nut.
Any idea where I can get one of those "end caps"?

Also, when I made my last adjustment in an attempt to ensure that it's "neutral", it appears that I have introduced a "shimmy" that I can feel in the steering wheel. It is quite annoying. Does that make sense?

It was not "neutral" for years and I just lived with it, but it also did not "shimmy"....
Is there some way I may have introduced this effect? I'm quite sure it's from my adjustments..... I'm going to go tweak on it some more, but I thought I'd ask first.

NeverTooOld

Try Wilcox for the cap and I would think you have a tire balance problem causing the shimmy; not the steering control valve. Is your front end tight or does it need new tie rod ends and ball joints? If they're loose they could be contributing to the shimmy.

DUB

I seriously doubt that you adjusting the control valve caused this 'shimmy'.

Keep in mind that you do not want to keep messing around with the nylock nut. IF you do....replace it with a new one.

I am also assuming that you did adjust the control valve balancing correctly.

DUB

HeadsU.P.

You introduced an air pocket in the system. The proper way to remove air is to crank the steering wheel ALL the way in either direction (with engine running) then crank the other way, lock to lock. Do this several times and any bubbles should work their way to the pump and disipate. Sometimes they don't.

I believe the shimmy is caused when an air pocket forces the PS cylinder rod out, or in, then returns to center briefly. Its very rapid and scares the H out of you going down the road. This happens when PS repairs were done without bleeding the system as described in the above paragraph.

To balance the PS Control Valve, put the front end up on ramps. Disconnect PS cyl rod at the end near the frame. With engine running, steering wheel centered, adjust the nut until the rod self centers, ALL BY ITSELF, and holds dead center. Then you know both left & right are equal. Re-attach cyl rod, install your lost cap, good to go.

carriljc

Thanks, I thought I may have introduced something along those lines. I just didn't know how to get rid of it. I will try that lock-to-lock and see if I can get rid of the air.
It is a bit scary. I was going to out for a drive just because I hadn't for a while and as soon as I got going I recognized that it was actually quite annoying and uncomfortable.
It's odd that I had not had any problems... even when I installed power steering some 20+ years ago. That's why I suspected that I had done something to introduce this. I hope that lock-to-lock exercise works, or I'll have to figure out another way to degas.

As far as the end cap, I may just go to the boneyard and hopefully find an old car.....

I did the disconnected cylinder adjustment and then I also did multiple adjustments over several days as I drove....just to try and get it really neutral. When I get under there again I will do the disconnected cylinder adjustment ......that is, after I do the attempt of getting rid of the air in there.

HeadsU.P.

It happened to me, miles from home and a half hour after I changed a broken PS hose. An air pocket or maybe a piece of dirt. Not a real shimmy, but sure felt like one in traffic. Since that scary ride, I now bleed the system first before test drive.

Its easier on the entire steering system if you do the lock to lock parked on dirt, sand. More giving than blacktop.

carriljc

haha...thx. I'll have to think of the nearest dirt

I'll be back for other venting options if cycling lock-to-lock does not work. Probably do that experiment in a couple of days.

'75

Like H.U. says, to balance the valve, disconnect the cylinder rod from the frame bracket, engine idling, adjust the nut till the rod just starts to extend, then turn the nut the other way counting the number of turns till the rod just starts to retract. Turn the nut back half that distance, that is balanced.

cagotzmann

Watch this, and forward to 5:50 minute mark.

Haggisbash

If you can't find a cap straight away to cover the adjusting nut, the protective cap that comes on some plastic soft drink bottles will fit with a dab of silicone, this will keep the dirt out until you can get the real thing.

carriljc

Many thanks ..... and, yes, I should do that till I get to the boneyard and hope they have some old GM cars.
From my recollection that system was used for years (if not decades?).

DUB

Or simply use your floor jack and raise the front tires off the ground.

The power steering system is self bleeding. BUT what can happen is if a person crank up the engine and the fluid carbonates....you must stop and allow the bubbles to surface in the reservoir. Then do the procedure again and look in your reservoir again for carbonated fluid. Carbonated fluid can cause for the system to act crazy.

Once you have no bubbles in the fluid you are fine. And while the front tires are off the ground or where ever you plan on doing this...rev the engine to 1500 RPMs while turning the wheel from lock to lock.

And IF you plan on doing this on pavement...,make sure to move the car forward or backwards a bit so you do not flat spot your tires. So if you go from one side to the other and then back...move the car...and so on. But I always have the front tires off the ground when I do this....but that is just me.

Why can contact LoneStar caliper and see if they can get a cap out to you. Seeing how we all know they rebuild them they do have that cap. If you were in my town I would tell you to stop by and I would give you one.

DUB

stevedinino

My 77 didn't have a cap on the PS control valve. I finally found one for a reasonable price at Rock Auto. It's not original GM, but it does have the 'C' stamped on it so it's good enough for me...

https://www.rockauto.com/en/moreinfo...024477&jsn=259

Shipping will be more than the price of the part, sadly.

HeadsU.P.

If the PS system were truely self-bleeding you wouldn't have to go through the procedure you describe DUB. One would just drive off into the sunset without any issues. I have had the steering wheel shimmy only once in 9 yrs. And that was within an hour of introducing air into the system, (hose replacement). The shimmy lasted only a few seconds until I pulled over and worked the air out. Scary stuff.

DUB

Not to make light of your 'scary experience' . Glad that you are okay.

It is a self bleeding system. GM's wording not mine. Obviously to make the p/s pump work is must be turning in order to circulate the fluid. The fluid circulates and makes it up to the reservoir and thus any air bubbles can pop and get out.

The system is not a closed system like a brake system. A power steering system has no bleeder fitting to open to get the air out. That difference may be why GM states it as a self bleeding system.

If needed...I can find the written text that I have read that GM states that is is a self bleeding system.


I can not help that the procedure GM has outlined of turning the wheels while the engine is running makes that much of a difference.

On my Chevy truck. It has a very slow leak in the p/s system. And the pump will run dry as a bone and I add fluid and drive it. No problems with that. And check the fluid when I get ready to go home and top it off and all is good until is has leaked out in a bout two weeks.

DUB

HeadsU.P.

Good enough. I'm thinking of forming a posse and get a bunch of C3ers and go linch the engineers who, or is that whom? designed the C3 PS system. Are you with me? I will bring the rope. Who knows how to make a noose?

Stephen Irons

I used the C&S video when I rebuilt my P/S valve earlier in the year and I have to say, its excellent! The only thing I do is to "bleed" the system without the engine running. With the car on axle stands I turned the wheel from lock to lock about 10 times. Seemed a little "kinder" to not start the car and stop it again, especially as it hadn't run for a month or two... Just me! Then started it and for the balancing. It worked fine and the valve balanced perfectly.

DUB

I am not with you on this one. Only because the power steering system... for me.... is not that big of a deal to get correct. There are other areas of the car that I wish that a bit more fore thought was used in regards on how to repair it when the car is assembled. And the 'funny' thing is that GM engineers figured it out and corrected it.

I can say that I honesty think that what GM did was just re-use the power steering system that they used on other GM vehicles like are what is on my '64 Impala....and not go through a total re-engineering of the system...that...back then...it did its job. And heck..they kept it to keep costs down on re-tooling until the 1984''s came out.

From a business point of view.. they were thinking smart. Because as you more than likely know...once the tooling is paid for. They are into making good profit..so it only makes sense.



I do the same thing when I am installing a hydroboost system with rack and pinion. It helps get the fluid somewhat flowing to where it need to go before I actually crank it and check the reservoir.

DUB