Power steering failure

So need some diagnostic help. I underwent a DIY passengers side drive axle replacement and brake caliper replacement. For reasons unrelated... I got the car jacked up and most of the parts out (couldnt get the drive axle out of the differential) and decided to bail on the whole project for now. I got the vehicle put back together and when I started it up I had terrible power steering pump noise and power steering was intermittent and then went out within a few seconds to a minute. I checked the reservoir and fluid was a little below cold min. I had started to notice a little power steering noise before starting this job... but nothing even remotely close to what im hearing now. I added fluid to just below the cold max line and started it back up. Same noise. checked the reservoir and volume had spiked to almost the top of the container. After shutting off the engine it settled back down to the line I had filled to. Also saw some bubbling in the reservoir. I noticed what I believe to be power steering fluid on the undersurface of both boots just proximal to the tie rod. I dont remember noticing this pre working on the vehicle. I did have to disconnect the passengers tie rod and then put pressure with a jack on the bottom of that tie rod to keep the post from spinning as I put the nut back on.

Any ideas? Air in the system? If so what do I do? A block in the system? Pump failure? The pump does sound loud when just idling... not turning the wheel. Gut feeling is pump is bad... but why all of the sudden right after I work on it... Too much of a coincidence and why does the reservoir volume appear to raise when vehicle is on and then settle again? Why the bubbling? PLease help.... am supposed to be taking the vehicle out of town.

 

I've read this three times and I still don't have an answer......

My only suggestion is to drain and refill the system.

Put your 4Runner on jack stands. Remove your front skid plate and follow the two hydraulic lines from your steering rack, High pressure is crimped hose, low pressure should have a clamp. With the 4runner not running slide the clamp back and pull off the hose and let the fluid drain into a bucket, while it is draining slowly turn your steering wheel back and forth full left and then full right several times to get the remaining fluid out of the system. Make sure to do this until it is totally empty. Reattach the hose and install clamp and fill reservoir and once again slowly turn your steering wheel all the way to the left and then all the way to the right and fill reservoir as you go until full.

 

@RonT4R thanks for the comment! I figured it out and thought I would share so you didnt pull your hair out I swapped pumps (tough job on a northern vehicle where everythings rusted) but it turns out it was the PS fluid reservoir. I found the solution on a honda forum first then came across it on a Tacoma forum... but hadnt seen anything on 4runner forums. Ill search specifically for it again. Anyway... seems our PS reservoir has a screen in the bottom of it to keep debris from making its way into the pump and the rest of the system and stroking the whole thing out. Coincidentally or maybe from jacking the car... this screen ended up clogged with debris preventing fluid from making its way to the pump fast enough. If the car sat, some fluid would slowly make its way to the pump and provide a very short and intermittent steering assist before it went out again. Its also why when I jacked the car to bleed the system the fluid would overflow the reservoir with each full crank. Holding the pressure on the wheel the fluid level would hold its line and only go back down if I took pressure off the wheel (fluid would flow back into the pistons I guess). It was moving into the reservoir faster than it could flow out. When I took the reservoir out I couldnt see if there was a screen or not... but I blew compressed air from the pump side of the reservoir and out came a bunch of crud and then you could see the shiny metal of the screen. After clearing and rinsing with PS fluid, when I bled the system the level would raise if I turned quickly but holding the pressure on the wheel the fluid would move readily out to the pump and the level would drop quickly. Fired her up and PS is back and pump is quiet. Pump may have not been a problem after all... but no way in the bad place am I swapping it back! Anyway... thanks for your empathy and feeling a touch of the frustration for me! Cheers!

 

swap the pump out as for the tie rod end stick a pickle fork between the tie rod end and the connecting point add pressure as you tighten up the tie rod that should take care of that problem. LARRY B.