Power Steering Nightmare

Hi Guys..
I've been dealing with a power steering issue that is making me nutzo and have run myself completely out of ideas.. Hopefully, you guys will see something I'm not!
My steering has hard (tight) spots in it when you turn the wheel such as in a turn or going lock to lock. It doesn't whine or leak, and in between these "spots" it feels like the power steering is working at least somewhat. It's really hard to describe this problem, I finally just let my neighbor take it out for a drive so we were working from the same sheet of music..

So Far, I've replaced or had rebuilt:
The rack (Shop rebuilt)
The power steering pump (new)
Replaced all the bushings (new)
Replaced tie rod ends (new)
Alignment
Tires (new)

*On top of the steering pump is a little valve with 2 vacuum lines going to it. Any idea what this does and could this be part of the issue? It's new as it came with the new steering pump.. Someone Please.. toss me some straws as I've run out of my own here!

~cork

 

Does sound related but wasn't there a power steering recall recently?

 

Maybe it's binding up a bit under the dash. That mini u joint in the steering shaft might need a little white lithium grease spray.

 

Ok, regarding the recall.. it's for the end plug on the steering rack.. Apparently, some folks have had leaks develop with the original ones.. I have lubed most everything from the wheel on down as this began with replacing the bushings wayy back when.. It's a hard problem to describe. I jacked the truck up and worked the steering back and forth but the "feel" changes and even though it takes less effort to turn the wheel, it feels like the condition is still there. I'm tempted to let the folks who rebuilt the rack take a look at it, but I don't want to get myself into a situation where I'm paying for someone's time rather than technical knowledge and that happens ALOT around here.. Anyone know the valve I've mentioned? It has a couple vacuum lines running to it, one from the valve cover and the other from the side of the airbox.. It seems to be a switch of some sort, but I haven't been able to locate it in the parts breakdowns I've been looking at. I guess I can always disconnect it and jumper the connection to see what happens.. I'll take a pic if anyone thinks that'd help,, Thanks for trying to help guys.. I'm alittle distracted with some medical stuff and havin you guys to bounce ideas off really makes a difference!

 

Following as my 10’ has been doing EXACTLY this since winter. Some days it’s fine but generally the colder it is the more prominent it is. Also from being slightly varying with throttle I was worried about it being the pump starting to fail but sounds like that wasn’t a solution for you.
No leaks that I’ve found either but it was a touch low when I checked it last year so I had added some Lucas additive like I normally do on my Subarus considering age. So I’ve questioned myself on if fluid pressure could “out of specified range” based on adding it, but seeing how Toyota follows the same on PS fluid as Subaru I guess that rules that out.

I can strongly agree with the thoughts of being more willing to pay for technical knowledge over their time. Part of why I might drop it off at a speed shop some friends own(multiple convenience of supporting friends, some of them have had Toyotas, and it’s right next door to my work) and seeing what they think. Frankly I feel like I need a once over on the truck anyways for a check up and see if the bit of hopping I feel from time to time is a caliper or the rear diff.

 

Just a quick update.. I kept thinking about this "different" way that the power steering pump mentioned in the paperwork of needing a vacuum pump to properly bleed the air out of the system. I've always simply jacked the front wheels off the ground and rotated the steering slowly back and forth, paying close attention to the fluid level. However, I had already done this twice and the problem still remained. So I broke down and spent the $80 for a vacuum pump off of Amazon and connected it to the return line to the reservoir. Since I was standing right next to it, I kept the reservoir topped off the whole time. Within about 3 pumps, I began to see air bubbles returning to the reservoir.. not just bubbles, but surprisingly large amounts of air! I kept pumping and topping off the reservoir and about a bottle and a half the air stopped coming out. I continued and poured the other half of the bottle through, but that was the last of the air as far as I can tell. When I took her out for a test ride all the "tight" spots had disappeared and while it isn't exactly the easiest power steering I've ever felt, it's clearly 100% better! Additionally, I pulled everything out to get at the "universal joint" that's sorta under the dash and sorta just outside the firewall and while it was pretty dusty/dirty, I cleaned it squeaky clean with carb cleaner and re-lubed.. Didn't make much difference. ** On a side note.. I purchased the hydraulic pressure test set to measure whether or not the system had the proper operating pressure but, I never got around to using it. It all works well enough for me now that I might eventually sell this test set. It was alittle pricey but, if you need one there's no real substitute way of testing that pressure level. Hope this helps someone!