BirdLS400

Also, the fluid has been very dark everytime I am into the job, so I think that leans toward a failing rack. Anyone have recommendations for a vendor for a reman rack?

Lavrishevo

iTrader: (1)

Rock Auto and google shopping. I don't think it's your rack. PS whine is not in the bottom rack. It's either the solenoid or pump and lines. Also, sounds like your have not flushed the system properly. Take at look at the solenoid as mentioned.

http://www.lexls.com/tutorials/steering/psflush.html

He mentions it can take up to 7 quarts to clean the old fluid out.

RA40

iTrader: (6)

This is a key point with it clogged. Those particles are also likely in the rack and even though the PS and lines are fresh, they are still having to push fluid through reduced passages/screens. Lavrishevo directed you.

Lexis0001

Mine would growl like that when it got cold. I put some Lucas oil power steering fluid/treatment and it smoothed out the noise.

LS400FAN

A clogged screen may be my problem. The sys was gradually topped off with Lucas stop leak over the past 2 yrs, and now it is not circulating through the sys. When the eng is running all of the fluid is being forced out thru the top of the reservoir, has anyone else had this problem? Secondly if the screen is in the reservoir I don't see how to gain access to it since it's pretty much a closed unit. Thanks much, this forum is absolutely tops.

Shiryo

I really didn't want to make another thread to the hundreds of PS threads, so I posted it in here... Is it me or is this the sound of a failing power steering pump?

The whole video up to the last 10 seconds I had my gf just barely moving the steering wheel side to side a couple degrees, just a tad bit of load on the rack and that's where you hear the variance in whining, however even at idle, you can hear it whining...

I'm not sure, but I swear I can even feel whatever is causing the whine in the brake pedal when sitting at a stop light. These symptoms only show up after normal driving for about 20 minutes...

[/youtube]

LS400FAN

I will attempt to keep my reply as concise and short as possible, but I want to inform as many of my fellow LS 400 owners as much as possible. Please take a moment to view the steps I've taken to fix my problem.

1. First of all, I DO NOT believe that Lexus makes a "bad" power steering sys, in spite of all of the posts that you read. The "leaks" in my opinion, usually occurs from the "hose" connecting the reservoir to the pump. It's hard to determine because it occurs on the "bottom" of the hose out of sight. The hoses get brittle ('98-'00)and leak. On the '90-'97, replace the rubber "o" rings where the reservoir goes into the pump.
2. When it comes to the LS 400 PS sys, - KEEP IT SIMPLE, don't start spending money replacing the units unless you know for sure what's causing the problem.
3. 1st step is to "remove" and thoroughly "clean" the reservoir (the screen inside gets clogged). I did this by spraying carb cleaner into it and blowing it out with compressed air. Even this wasn't enough so I soaked it overnight in hot soapy water, rinsed it in hot water and blew it dry with compressed air. It did the trick, I could clearly see the screen inside was CLEAN!
4. For the '90 - '97 LS, removing the solonoid and cleaning the screen is a good idea, removing the solonoid on the '98 - '00 LS is not easy so I would leave it alone (different sys).
5. Next, as mentioned earlier, replace the hoses to the reservoir and reinstall the reservoir.
6. Next, bleed the sys, there are several posts on how to do this, I recommend disconnecting the "return" hose from the "rack" and let the fluid drain. While its draining (with eng off and front tires off the ground, "slowly" turn the steering wheel all the way left, then righ several times, until all of the fluid is out the sys.
7. Next I rec using Mobil fully synthetic ps fluid (a little bit more than 1 qt). Bleed the air out of the sys, and it should eliminate most of the problems with ps sys imo. The noise could be anything from low fluid, air in the sys (usually caused by the "leak"), or the worst case scenario, a bad pump.

I'm a big believer in doing the SIMPLE things first, which is cleaning the screens, replacing the reservoir hoses (and o rings), flushing the fluid and bleeding the air out of the sys. People have spent hundreds of dollars replacing things that are not the problem and overlooking the SIMPLE stuff. I hope this helps, good luck.

Shiryo

My issue ended up being low on fluid, just barely touching the end of the stick, was just soooo busy past couple weeks, it never came to mind, stupid.

Another thing I want to mention is that the PS fluid was green. I had the impression that Lexus PS systems used Synthetic Dextron III fluid (Mobil 1 Synthetic ATF seemed popular) , wouldn't that be red? So i'm guessing there's cheap PS fluid in there.

So I will actually remove the solenoid and reservoir in the next coming weeks, clean and then flush the system and replace hoses if necessary and use Mobil 1 Synthetic ATF as a replacement.

andrewkran

yeahh i think its pretty common that the power steering fluid drains quickly and i also often get this grinding sound at low speeds when turning, the housing for the power steering fluid i think is not very durable and lexus should have fixed recalled this long ago, but just keep adding fluid every so often, and you'll be fine

LScowboyLS

the only time my leaking PS pump makes noise is when I forget to add fluid and it gets low

sam12345

iTrader: (1)

I removed the screen and put an inline filter. Every so often I pitch the filter and put in a new one. I also changed to mobil1 fluid and I also suck up the reservoir and put new at every oil change. Steering runs good.Also a common leak is the oring between the reservoir and pump and the idle up valve (one with the vacuum hoses)

LS400FAN

Make sure you install new hoses and o rings if you have a '90 - '97 LS, "bleed" the air out of the sys after flushing and cleaning the screens. The shop manual says you do this with the front wheels jacked up off the ground and the engine OFF, then "slowly" turning the steering wheel lock-to-lock about 8-10 times. Then do the same with the wheels on the ground and the engine RUNNING. I honestly believe you will only have to do this once every 50 - 60k miles and maybe even longer if you're using synthetic ATF. Good luck.