Power Steering & Smoke Problem - Ls 400 '92

[leftfooter]

I've been topping up my power steering fluid on a regular basis over the past 4 months. Can't seem to find a leak though. When I open the reservoir, the fluid appears frothy, like it has air bubbles in it.

In the last few weeks, Blueish/Blackish smoke bellows out of the car on startup. After startup, it appears to run fine. I did an earlier search and someone had a similar problem. It was suggested that it might be a faulty vacuum valve, on the PS pump.

The previous poster never responded with the results of changing the vacuum valve, so I don't know if that was actually the problem.

If you think this is the problem, I would be very interested to find out where is the best place to secure a vacuum valve for a PS pump. Also, anything I should look out for when replacing it. In this economy, Price is of the utmost importance!

Many Many Thanks in Advance!

suggestion from previous poster:

"Sounds like you have a faulty vacuum valve (located on the PSteering pump).

If that valve fails, power steering fluid gets sucked

into the engine's intake manifold and will cause

your engine to smoke. Install a new vacuum valve

on the PS Pump. "

[AzHotLS]

Yes, it's the valve. Did you see this thread:

http://us.lexusownersclub.com/forums/index...?showtopic=6583

Sorry, I forgot where I bought mine for my '90. It might have been AutoZone. I do remember it was about $80 though.

Here's a diagram of it:

http://www.toyodiy.com/parts/p_U_1991_LEXU...4.html?hl=17630

Search for part number 1763016040 (updated part number) at Carson Toyota:

http://www.trademotion.com/partlocator/ind...m?siteid=214915

[leftfooter]

Yes, it's the valve. Did you see this thread:

http://us.lexusownersclub.com/forums/index...?showtopic=6583

Sorry, I forgot where I bought mine for my '90. It might have been AutoZone. I do remember it was about $80 though.

Here's a diagram of it:

http://www.toyodiy.com/parts/p_U_1991_LEXU...4.html?hl=17630

Search for part number 1763016040 (updated part number) at Carson Toyota:

http://www.trademotion.com/partlocator/ind...m?siteid=214915

Thanks AzHotLS. I hadn't found that other post but it was very informative. The one thing that they didn't clear up was the color of smoke. They mentioned a White puff of smoke but mine is definitely a darker hue, blue or even black. One guy mentioned that it was the pressure switch on the pump, and that the O-Rings needed to be replaced. Do you think that BOTH the ACV & the pressure switch/O-Rings need to be replaced? Or should I start with the ACV and see how it goes?

Lastly, if the ACV is replaced, will that fix the constant topping up of Power Steering fluids?

Thanks again for replying.

[AzHotLS]

Like yours, mine was blue. I'd start with just the ACV. It's what is allowing fluid to be sucked into the intake manifold and burned out your tailpipe. Yes, once you replace the ACV, no more topping off.

ADDED: Before you remove the ACV, be sure to cover the alternator. You don't want to get fluid into it and ruin it. Then after it's replaced, check back to make sure it's all dry down there to see that you don't have any other leaks.

[RDM]

You can also just bypass it completely, buy a pipe plug the same size and thread it in, then cap the vacuum lines. Steering isn't altered much if any from the year I've driven without it. Beats having to replace a leaking valve every few years and clean out the intake manifold.

[90LS400Lexus]

I did an earlier search and someone had a similar problem. It was suggested that it might be a faulty vacuum valve, on the PS pump.

The previous poster never responded with the results of changing the vacuum valve, so I don't know if that was actually the problem.

That would probably be me. :) I never checked it, so I am not sure. I am not that mechanically inclined and I cant afford a new pump. Just keep adding in thick PS fluid. <_< I have a older car (but a gas hog) that I am about to start using as a daily drive and continue to use my trusty 80s Mercedes on my days off and park the Lexus for awhile. :)

4 times out of 5 it will smoke when first started and it is indeed the PS fluid, because it dont smell like oil.

I am about to just have one of our mechanics to quote me a price to rebuild the pump (if thats possible), because I have been wanting to give the car to my mother.

I have been reading something about bypassing the valve, but I think that only takes care of the leak where it pulls the fluid it into the engine.... not sure if that eliminates where it leaks down on the alternator/under pan??? Can someone verify that? I am guessing worn seals is the cause of that.

Good luck!

[RDM]

I did an earlier search and someone had a similar problem. It was suggested that it might be a faulty vacuum valve, on the PS pump.

The previous poster never responded with the results of changing the vacuum valve, so I don't know if that was actually the problem.

That would probably be me. :) I never checked it, so I am not sure. I am not that mechanically inclined and I cant afford a new pump. Just keep adding in thick PS fluid. <_< I have a older car (but a gas hog) that I am about to start using as a daily drive and continue to use my trusty 80s Mercedes on my days off and park the Lexus for awhile. :)

4 times out of 5 it will smoke when first started and it is indeed the PS fluid, because it dont smell like oil.

I am about to just have one of our mechanics to quote me a price to rebuild the pump (if thats possible), because I have been wanting to give the car to my mother.

I have been reading something about bypassing the valve, but I think that only takes care of the leak where it pulls the fluid it into the engine.... not sure if that eliminates where it leaks down on the alternator/under pan??? Can someone verify that? I am guessing worn seals is the cause of that.

Good luck!

First off, if you're using PS fluid, no wonder it's leaking. Toyota calls for the use of ATF in the power steering system. There's a ton of good resources explaining why.

If you bypass the valve, you're plugging the hole completely. As long as you seal it with something, any leaks you may have had are fixed. Typically I just smear a little RTV on the threads before installing, telfon tape works too.

You can buy a reman pump for about $130 at most auto parts places, I've had one for four years now, no issues. Just make sure to flush the system thoroughly first, especially if it's full of regular PS fluid.

[90LS400Lexus]

I did an earlier search and someone had a similar problem. It was suggested that it might be a faulty vacuum valve, on the PS pump.

The previous poster never responded with the results of changing the vacuum valve, so I don't know if that was actually the problem.

That would probably be me. :) I never checked it, so I am not sure. I am not that mechanically inclined and I cant afford a new pump. Just keep adding in thick PS fluid. <_< I have a older car (but a gas hog) that I am about to start using as a daily drive and continue to use my trusty 80s Mercedes on my days off and park the Lexus for awhile. :)

4 times out of 5 it will smoke when first started and it is indeed the PS fluid, because it dont smell like oil.

I am about to just have one of our mechanics to quote me a price to rebuild the pump (if thats possible), because I have been wanting to give the car to my mother.

I have been reading something about bypassing the valve, but I think that only takes care of the leak where it pulls the fluid it into the engine.... not sure if that eliminates where it leaks down on the alternator/under pan??? Can someone verify that? I am guessing worn seals is the cause of that.

Good luck!

First off, if you're using PS fluid, no wonder it's leaking. Toyota calls for the use of ATF in the power steering system. There's a ton of good resources explaining why.

If you bypass the valve, you're plugging the hole completely. As long as you seal it with something, any leaks you may have had are fixed. Typically I just smear a little RTV on the threads before installing, telfon tape works too.

You can buy a reman pump for about $130 at most auto parts places, I've had one for four years now, no issues. Just make sure to flush the system thoroughly first, especially if it's full of regular PS fluid.

No, I am not using PS fluid... and the ATF goes right through... all it will hold for any time now is the Lucas PS fluid and its $10 a bottle. Last time I drove it (Saturday) it was very low again and I was not going to drive it again until it was repaired, but I will have to drive it again tomorrow for about 20 miles.... then I will probably park it until we get it fixed.

[90LS400Lexus]

I also didnt know that a new pump could be bought at a auto parts shop.... thanks for that RDM. I thought it was a dealer only item! I found a pump as low as $139 at O'Reilly. I think its a Cardone? I know someone that will install it for about $50. Does anyone know if this pump includes EVERYTHING needed to stop a leaky pump? Is that valve included with it?

[AzHotLS]

Does anyone know if this pump includes EVERYTHING needed to stop a leaky pump? Is that valve included with it?

I'm fairly certain that I've read in other posts that the AVC is the only thing not included with a new PS pump. It's easy to verify though. Look at the pump, if you don't see the black valve with two posts for the vacuum tubing, then it will need to be transferred from the existing pump, or buy a replacement.

Also, most mechanical parts can be bought at the parts store. Quality? Well, you'll get a ton of opinions both ways.