3.4L Power Steering Pump Whining Excessively
 

Hello all. The power steering pump on my rig started to whine more than usual today (used to do it only when cold in the morning) and its unbearable to hear. It gets worse when turning the wheel which pretty much says the power steering pump is in trouble. Wheel is also stiffer than usual. I hate to say this but the fluid hasn't been changed in forever and now i'm kicking myself for not changing it sooner. I have linked 2 YouTube videos down below so you guys can hear the pump in action.

I'm going to be starting off with a power steering fluid flush and see where this goes but if you guys have any sort of advice on my problem, I would really appreciate it. Truck is now going to sit until fixed. Thanks all!

2000 Toyota 4Runner Power Steering Pump Whine - YouTube

3rd Gen 4Runner Power Steering Pump Whine - YouTube

If you’re going to flush the power steering I highly recommend removing the reservoir and cleaning the screen in there. 3 bolts to get it loose and an o-ring. If you want to replace the o-ring it’s 90301-11016. I had to soak acrysol in mine and shake it to get the screen clean.

@ Bad Luck beat me to it. I agree with what he said and I'll take it one step further and link the video I made cleaning the reservoir on our power steering pumps.

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Yep, watched Timmy the Toolman's video on the power steering flush and will start off with brake clean and see if it knocks the grime off. I'm not going to be replacing the small gasket because I do have a chance of replacing the entire PSP if the whine doesn't go away.

Loved your video Timmy!! Your video will be my guide to flushing the fluid on my rig and i'm hoping the whine goes away. I'd say that my fluid wasn't changed in 10+ years but thats going to change really soon. Just have to go to Home Depot first and get the necessary hoses and clamps for the job.

Don't discount the Whine being the AC Idler pulley.

I had a whine that I SWORE was the Power steering pump, sounds pretty close to yours. Flushed fluid multiple times, screen was clean, and no dice. Replaced the pump, still noisy.

AC Idler pulley was causing all the noise. It seems counter-intuitive, but trust me. It takes 2 minutes to check the AC Idler pulley. Just back off the main nut and adjuster until its loose and you can spin it by hand. If it feels notchy at all, there you go.

Going to be noting this if the problem doesn't go away. Good thing its easy to swap out the pulley.

As of now, I just got done cleaning the PS reservoir (completely blocked of junk!) and hooked up the return hose routing to the bucket. Just waiting for a relative of mine to start the rig up and let the pump do its work while filling up the reservoir. Everything has gone very smooth.

I got done with the power steering flush earlier today and even though all the old fluid got flushed out successfully and used Valvoline DEXRON III as the replacement, the damage was done and step 2 is to now replace the power steering pump itself. I went to check the truck again after sitting for an hour and the same whine is there but a little quieter.

I also checked the reservoir after the drive and found the fluid very bubbly even though I let it sit for some time. Would leaving the cap on make a difference? Thats what I did.

Also discovered the idler pulley shot and replaced it with a NAPA pulley hoping that was the source of whine but its not.

Let's see if it stops after you get all air out of it and at the proper fluid level.. If it was starved for fluid long enough it very wel can be damaged. :(

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I'm definitely sure it was starved for a long time as the reservoir screen was completely clogged and showed early signs of failure (whining on cold starts but goes away when warm). Cleaning it was the best thing I can do for it. I will be leaving the cap off the truck tonight and see what happens in the morning. If it whines again, its definitely new pump time.

To bleed the power steering system, you want to start with the front wheels off the ground and with the car running turn slowly lock to lock a couple of times making sure to top off the fluid as the air escapes and the fluid level drops. Then put the front wheels on the ground and continue turning lock to lock a few more times. Watch the fluid level and keep topping it off. Once the level stops dropping you are good to go. Until you bleed the system it will make terrible noises when turned hard in either direction.

I once had a loud whine and thought it was the PS pump so I replaced it. Started her up and still had the whine. Turns out it was the damn AC clutch bearing making all the noise. I learned my lesson and the value of making a proper diagnosis!

Checked the 4Runner this morning and the level dropped a bit so I added more ATF. Before firing the truck the fluid had no air bubbles but after running it, the air re-introduced itself.

Same exact noise. I was also thinking inside my head and remembered this; when the fluid started to pump its way out, it was completely filled with air bubbles and same with the new fluid on its way out - filled with air bubbles. I turned the steering wheel lock to lock slowly and still the same whine.

I inspected the hoses to see for any leaks and all is good (wasn't losing ATF so I knew the lines were good). I'm going to pull the trigger for a reman pump and see what happens.

Do you hear the whine only when at full lock, or is it constant?

Whine is heard when truck is running and gets louder when turning the wheel.

Just removed the entire pump and discovered the O-ring destroyed due to installation. I already ordered the reman at NAPA and its ready for pickup..... Going to be replacing it anyways since the original had 230k.

EDIT: Decided i'm going to be rebuilding my factory pump with the rebuild kit and see what happens. I don't feel comfortable using the reman from NAPA and will be returning it tomorrow. Read a bunch of horror stories about the reman pumps not working as it should - sometimes right out of the box they don't work.