joelchicago

Guys,

A little while ago, there was some talk about PS system noise when cold. Mine is getting worse, and the fluid smelled burnt (and it's dark) when I checked it this weekend. The pump is newer (3 months or so). Does this mean that the fluid is not circulating properly?

I've talked with the Lexus rep here, who thinks I should replace the rack. I won't do that unless I know for sure. I know it was said that there could be something blocking the rack at its filter or something, but no one I've talked to will back that up.

Any ideas on flushing this system and fixing this? The whine is getting bad, and I don't want to burn out a new pump!!!

Purplexed

A fellow by the name of DevilDogIS300 answered this one a few months ago.
I will copy the post for you. Also, did you do a COMPLETE replacement of the fluid as per the manual. Not just add some fluid'. I am ASSUMING your filter is clogged, give it a try.
I just copied the correspondence for you. Think you can get the gist of it. Good luck
The thread read as follows for a LS400:
It's a great idea to flush that power steering system out every 45k. The fluid always gets that way on Lexus vehicles. I have never used synthetic pwr str fluid before, no comments on that. Two suggestions: 1. When the fluid is drained, look inside the fluid reservoir with a small flash light. There is a metal screen at the bottom that will become clogged with particles. If so, you can either remove the fluid reservoir and try to clean it with brake cleaner. Or take a long philips head screw driver and simply poke a small hole in the center of if. That will helps circulation of the fluid. 2. Remove the solenoid on the rack and pinion. It also has a screen that must be cleaned. I have seen so many of them clogged. It's a plastic screen and can be sprayed with brake clean as well.

The pressure control valve does have three bolts. It is a large valve that has two wires coming from it. The valve it's self faces down and must be tapped off with a screw driver


To get to the solenoid screen the entire solenoid must be removed. Unplug
the wire connector first, if you look at the base of the solenoid it looks
like you need a huge wrench to remove it. I simply tap it with a large
screwdriver and a hammer right on the edge where the wrench would go. Once
you get it started you can remove it by hand. Watch for an o-ring on the
rack and one on the solenoid. The one on the rack could fall off, simply put
it back on. I don't think you'll need an additional filter, just something
else to clean later. After you remove all the fluid and clean the screens be
sure to top off the fluid before you start the car. Then when you start the
car be ready to immediately add more fluid. It is normal for the pump to
make a whine noise for a while. That's just air in the system. If you do get
allot of air in the system then simply turn off the car, leave the reservoir
cap off, and let the car sit for about two hours. The air will rise to the
top. With regard to the reservoir screen, if you don't feel comfortable
removing it then I would just poke a small hole in it. The solenoid screen
will catch allot junk before it gets to the rack.

ToyLexmods

Joel,

This is good info and the screen I was talking to you about. Its under the solenoid valve. The most important thing for you to check is if your ps system was flushed after the pump replaced? If not....then flush it and remove the solenoid valve to get at that screen.

joelchicago

Took apart PS reservoir tonight. Some blockage, but not bad. Drained the rack by turning back and forth (black fluid, not red at all anymore). Tried to refill just to see what would happen. NO FLUID LEAVES RESERVOIR! Something is 100% blocking the fluid path.

I couldn't get to the solenoid - couldn't figure that out. Any more detailed info out there? I saw it, but how to get at it for removal??? At any rate, no fluid would go in system when car was running, so PS pump is making a big racket (and not just a simple whine - this is a different sound than the subtle whine I had!)....

Turned off car and suddenly fluid starts shooting out of reservoir all over the place(with gobs of tiny air bubbles in it)!!! What the?

Any ideas folks? I'm about to bring this thing in for a new pump or rack if I can't figure it out real soon. Could solenoid screen be THAT blocked??? Seems like way too much backpressure and 100% blockage!!!! where do I get cheap parts??

HELP! Car is on jacks, PS res and intake out, cover off bottom, ready to go, but I'm almost afraid to mess with it much more - what a monster!

Thanks for the help so far!!

ToyLexmods

Joel,

Clarify....how you drained the rack? turning back and forth? how did this drain the rack? did you remove some lines....and most importantly....was the car running when you turned back and forth?

joelchicago

With the car OFF, I turned the wheel full back and forth. I'm sure I didn't drain all the fluid, but I emptied a LOT out - it all shot out one of the reservoir hoses as I went back and forth, car off, wheels in the air. I imagine the remaining fluid is in the rack, but I got about a quart from the system after the reservoir emptied.

I saw the solenoid, but couldn't get it off - tough to get at too. The wheels turn easily yet - no problem there. Just no fluid getting from res through pump, it appears.

ToyLexmods

Joel,

There is a procedure to flush....its not what you did. I donno if that messed anything up. Its very important never to let the pump run without fluid....it must be filled at all times or its toast.

I donno if a blocked screen could just pop up like this. You must have introduced too much air into the system and must bleed it good.

joelchicago

I figured flush was incorrect, but I also figured if I could get fluid back in fast, my pump is already hurt, so it's not gonna get a lot worse.

Tonight, I started the car and ran it while turning the wheel back and forth again. A minor miracle appears to have happened. Still have slight whine from PS pump, but the previous horrible noises are gone. The fluid worked its way in. I guess some air rose while the system sat overnight?? I dunno. All I know is that the fluid is fairly clean (looks like I got a whole lot of the old stuff out) and the PS pump is 100 times happier than it was.

I still couldn't break the solenoid loose - chipped the metal away, but didn't loosen the nut. That's OK - appears that the car is 100% happier now and fluid is flowing properly. I took apart the reservoir and cleaned the screen. There was caked something on the upper part of the reservoir and that was flaking and falling into the screen. Maybe that was making the biggest problem (in addition to that horribly burnt fluid). I plan to still replace the pump eventually, but I'm back on the road. Previous owner must have just not flushed the system after changing the pump - AND he overfilled the reservoir.

black sc

The correct procedure is to lift both wheels off the ground and requires two people to actually do it. One starts the car and turns it off after a second while, the other fills the resevoir. It goes down fast and you cannot fill it up fast enough. The other person in the car will not even have enough time to turn the wheel. You have to do this at least 3 times if, you have air in the p/s system. This procedure is normal not just for the Lexus but, for most cars as well.

My suggestion to you is to buy the Lexus manual. It'll costs a lot less than a new steering rack and/or pump not, to mention time wasted.

Purplexed

Is there a doctor in the house?
Has anyone successfully removed and replaced the screen, and if so how ?

Camshaft

Anyone have the process yet? With the weather warming up, I will try to make more wrench time.

toddatroos

Hey guys...

I've been fighting this same problem on my LS for about three months. I did manage to get the solenoid off to clean the filter screen out. Jack the car up and take the left front tire off. Take the two bolts out of the pressure valve that is mounted to the rack and also disconnect the high-pressure lines from the back. Once you have the two bolts out, you can twist the whole thing around so you can get to the three bolts out of the housing the solenoid screws into. I took the housing with the solenoid in it completely out of the car so I could get at the solenoid better. A couple of whacks with a screwdriver and hammer broke the solenoid loose. The screen filter is a collar that goes around the neck of the solenoid. Mine was completely plugged with metal particles. Clean it out with some brake clean or something similar. When replacing the components, replace the O-rings under the solenoid housing. Mine leaked the first time I put it back together.

Anyway, after all that work, I still have the same problem with the P/S fluid "foaming". The steering worked much easier and better after cleaning the screen filter, but the noise from the pump is still there. I have tried poking a hole in the screen located at the bottom of ther reservoir, but it didn't help. I am going to check the reservoir better to see if it still might be plugged up. I will also try "burping" the system better as described in this post.

Hope that helps with the filter screen.

joelchicago

Yep - foaming = air in the system. My suggestion is use the method of front wheels up, then turn all the way, leave there a couple seconds, then come back. I did this several times and then had to let the car sit an hour and did it again. That worked for some reason. Plan on replacing your pump though - with an air pocket, your pump noise means it's done, just like mine!