can i adjust (tighten) the ball stud on the power steering control valve?
mine has about 1/2" of play at the top it...but it dosnt leak...

 

The only adjusment possible is the centering adjusment. I would just replace the unit, Zip offers a rebuilt one that has a much better warranty than a new one.

 

ya...thats what i thought too...at $79.95 it would be an easy and reliable fix...
over and done with...

 

The ball stud is adjustable but you must disassemble the valve to make the adjustment. I adjust them to zero clearance during a rebuild. There is a metal gasket between the two halves that must be replaced when you do a rebuild. It comes in the kit. Of the tons of valves I have rebuilt, I was successful only a few times re-using the gasket after it was compressed... it tends to leak when re-used.
Also... to avoid damaging steering components do not use a pickle fork to separate the ball stud from the joint. Use a pitman arm puller. I use an OTC unit that does not damage anything during disassembly.

If you have any questions, please email me... I do not come on here much any more and I check my email every day.
Tom

 

Zip has the best instruction so far.
http://www.zip-corvette.com/controlvalve.htm

The adjustment is done in moment 11.

Good luck!


[Modified by Lasse, 3:10 PM 1/26/2003]

 

OOPS !! I guess I spoke too soon. Now I know. I tried to rebuild one once but the pitting and corrosion was too bad so I replaced it.

 

Are you checking the play in the ball stud while the engine is off? If so thats why there is play. There should be then. When the engine is running the valve is pressurized and the play will go away. I noticed mine moving once before like you say. Then when i checked with the engine running the play was no longer there.

 

wow...i did not know this...
yes...i checked it with the engine off...
ill re-check it tomorrow...
thanx ya'll!

 

I have nothing to offer here but "Sloppy Ball Stud" was my call sign in the Navy.

 

No there shouldn't. Do your tie rod ends loosen when the engine isn't running?
Your ball stud is loose and needs adjustment. the hydraulic pressure in the control valve is just taking up the slop in the balljoint when the engine is on.

 

MikeC, this is the way I understand it to work. The ball stud on the controll valve senses when there is pressure put on it by the pitman arm. When you turn your wheel to the left, the pitman arm pushes on the controll valve stud in that direction. That force against the stud opens fluid into the ram to assist in the effort to turn the wheels to the left. Therefore, the controll valve stud has to be able to move in each direction in order to give the command to send fluid to either direction of the ram. Its when the engine is not running that there seems to be excessive play in the controll valve stud. With the engine on and the power steering system pressurized the play is practally non- evident. Tierod ends are totally different in respect to thier function. They simply act as a conecting link between two suspension components, whearas, the controll valve stud has a function of connection as well as commanding which direction the fluid should flow to the ram. Im not an expert by any stretch of the imagination, but this is how I understand it to be. If im wrong, will someone please explain in a manner that we can understand. Ive been wrong many times before. I could be this time. But I doubt it.

 

You're absolutely correct John. If the steering valve has all the play adjusted out when the car isn't running, the power steering system can't work properly if at all.





[Modified by Solidlifters, 10:14 PM 1/27/2003]

 

Y'all sound like the dudes in the poem ... Three Blind Men & The Elephant... :)

The ball part of the ball stud is enveloped by two hemispheres for retention.
The hemispheres are encased in a sliding cylinder which moves independently of the valve body.
It is the sliding of this cylinder which activates the hydraulic circuits for a left or right turn.
The cylinder touches/moves the internal hydraulic valve.
The small adjustment on the outside (which everyone is aware of) simply centers the valve internals so that the internal piston/valve is equidistant from the left & right turn ports.

The ball stud MUST be tight between the two hemispheres in order for the steering to function properly. This is the "internal adjustment" that most people are not aware of. To be aware of it, you must totally disassemble a valve to learn how it works.

There should be ZERO play between the ball and the two retaining hemispheres.
There is no way to know the state of this adjustment from the outside aside from it being extremely sloppy... you have to have the valve apart to make a determination.

With the engine on or off, the ball stud, hemispheres, cylinder and hydraulic valve can move whether the ball stud is properly adjusted or not. That's the way the design works. That's why you have to take it apart to determine if the adjustment is necessary unless it is extremely sloppy and obviously messed up. To make that judgement call, you have to take a few of them apart and gain the experience.

Hope this helps.

 

Couldn't have expressed it half as good as you did Tom!

 

"Y'all sound like the dudes in the poem ... Three Blind Men & The Elephant... "

I don't see the contradiction between what you've posted and what we've been talking about already???????? I've probably replaced 50 or 60 valves in the "shop years" (now behind me thankfully) and pretty well understand how they work, although I quit trying to build em myself after the 2nd one. I guess the point is that people who are unfamiliar with the valves mistake the movement in the stud in relation to the housing as wear, and that it must be there for the valve to function.


[Modified by Solidlifters, 1:56 AM 1/28/2003]

 

Welcome back (for the moment) Tom.
I've always found your descriptions and explanations to be very good.

Keep stopping in, so we can learn more.

Damn - I don't want to rebuild mine, yet. Maybe next winter.
:seeya

 

i cant let that one slip by un-noticed...it was TOO funny!

to the rest of you...wow...VERY informative! although no im even more confused! :lol:
it DOES move about 1/2" back and forth with the engine off but it DOSNT move with the engine running...
so.....?
im not really sure wether to replace it or not or if it will help me or not...
hhhmmm...?

 

ttt :(

 

Since I rebuild/service these for my own customers... I have new GM PS control adapters "on the shelf". I can pull one out of the box to see how much movement there is "with the engine off" on a new valve (not rebuilt). Rebuilt valves with high mileage are a bad investment because of the wear that occurs between the outer diameter of the internal sliding cylinder and the inside face of the adapter. As far as I know, the cylinder is not available as a separate item, so if it is worn, a rebuilt adapter is basically useless and tends to develop leaks sooner because of the loose tolerances. The internal seal fails. The inside of the adapter also wears, and no amount of adjustment is going to remedy this problem.
This is why I recommend a new valve in many cases instead of a rebuild. But the only way to know the condition of the internal parts is to disassemble the adapter.

As a side note, GM used to sell a "ball stud repair kit" that included the two hemispheres, a ball stud, spiral spring seat and seals etc. I have a few of these kits laying around, but I don't think GM sells them anymore.

I'll put a sticky note on my forehead to remind me to check the movement in a new control adapter for you tonight.

Tom

 

I got that repair kit from GM last year..... if memory serves me, it was the last one in Canada and the item was dicontinued.

It made it 1 1/2 years with only minor leaking....... ti still holds most of its fluid too bad my engine decided not to hold onto its bearings..... Oh well I wanted to do a Frame off anyways!