Power Steering Control Valve Leak

[RobotMan 264]

During the resto of my son's mustang I rebuilt a control valve for the power steering unit.  I have noticed a small annoying leak.  After putting up on lift and actuating several times I determined the fluid is leaking out of the boot area where the joystick goes in top of the control valve and the pitman arm connects.  Was I fooling myself in thinking I would be able to rebuild the old valve with a new rebuild kit and have it not leak?  Also, appears to be weeping from the endcaps as well. Comments, thoughts, or experience welcomed on how to proceed.

 

Thanks

Rick

[shelbyshelby 52]

I can't answer your question but you're scaring me, I've got one on the bench now. I have all seemingly good pieces but waiting on a new copper bushing that goes in the tube. My new gaskets are very thin. Wondering if they are oem quality.

[lanky 44]

I can't blame either of you for trying! I now wonder if I would have been better off trying...

[1969_Mach1 333]

Leaking past the spool valve?  What condition was the spool valve where the seals ride?  Are the seals for the spool valve installed correctly?  Spool valves are available but the cost is very high.

[RobotMan 264]

Been a while since I rebuilt it but all appeared good when I put it together. Nothing seemed out of place. Such a pain to get it out just to check it.

[1969_Mach1 333]

If I remember correctly, where you are seeing leaking could only be from either the spool valve or the smaller valve below it, which looks like a small spool valve.  It's been a while since I rebuilt a control valve.  I believe the smaller valve has end caps with an o-ring on each end cap, and each end of the spool valve has a lip seal with a plastic back up washer.  Hopefully something is simply wrong with one of the lip seals or o-rings.  Unless I am mistaken, there are no other gaskets or seals to prevent power steering leaks in the control valve.

 

If you have to remove it again, do yourself a favor and get a tie rod end remover.  They come in a couple of sizes and you will probably need the larger of the available sizes.  Don't hit it with a hammer or try to use a pickle fork to remove the stud from the steering arm. 

[RobotMan 264]

Thanks. Appreciate the advice.

[skidmarky 50]

I just went through this, got it back together last night and no leaks. Dan at Chockostang helped me out. Mine was rebuilt by Dan 5 yrs ago, installed without a pump (doh!) and driven a few times. Apparently driving without a pump allows the spool valve to move too far, which can push the seals out. This was the case. Luckily it only involved removing the control valve housing and replacing the seals, which I did without removing the whole thing from the car, simply unbolted the housing. There should be no fluid in the end cap, if its leaking from there I would bet the spool valve seal is leaking.

[1969_Mach1 333]

Maybe driving it without fluid in it damaged the spool valve seals.  Hard to say because it will definitely travel farther with the engine not running.  I vaguely recall there are mechanical stops to limit the spool valve travel.  Otherwise, every time someone pushed or moved a car without the engine running the spool valve seals could be damaged.  The Ford shop manual has a bench test and measurement spec for the spool valve travel.

[RobotMan 264]

I removed the spool valve housing today and removed the spool. Did not see any apparent damage to any of the seals or parts. Not sure how to proceed. Anyone try using a Lucas type stop leak for power steering? Wondering if it is leaking just because parts are original and a bit worn even if seals have been replaced. Thanks for your advice.

 

Rick

[barnett468 418]

There is around 2000 psi in the lines and additives like lucas are band aids and won't likely stop the leak.