It doesn't happen all the time but it happens in summer time when outside temperature is high and engine is hot. Small, fast, low vibration sound of purr when trying to turn in low speed. I've had this problem for a while and have been living with it. I don't know if it is related but I've always been losing fluid little bit. Would love to fix the problem if I can.

Anyone with some problem?

 

Very much sounds like power steering fluid leak problem to me. I've had the same issue with two other vehicles and now my newly-purchased 94 LS400. Have filled the resevor three times in the last six weeks. According to LSCowboyLS (an expert with this issue) it's a common problem with the LS and is a simple O-ring replacement. It can become an expensive alternator replacement if not fixed. I would recommend finding his "fix-page" and I think you'll be OK.

Good Luck,
Sammy

 

Sammy,

Simple O-ring replacement!!!

I've been searching for the information in this forum with no avail. If this o-ring is causing the fluid to leak to alternator, this is exactly what I was afraid of and was unable to verify. Where can I found a thread? Is there anywhere it describes the procedure on how to replace the o-ring? Or what words should I use to search? Thanks in advance.

 

It is more than likely the vacuum switch on the side of the power steering pump. There are a lot of threads showing how to take this piece out and replace it or modify it to stop the leak. I took mine out, replaced the o-ring gasket, welded the top shut and blocked off the vacuum lines at intake. no more issues!

 

Pump is essentially same in procedure. This thread has a diagram so that you can see the O-rings and placement.

https://www.clublexus.com/forums/ls4...00-ls400s.html

Finding the thread I have in mind has been I just read it a day or so ago.

 

This thread is in a sticky at the top of the forum for FAQ's on early LS400s, tons of info, be ready to read, lol.
https://www.clublexus.com/forums/ls4...ing-bible.html

 

Many of the links to lexusownersclub.com are not found and none of attached pics are not viewable. Is it just me or is this the case for everyone???

 

Unfortunately this comes with time and changes to off site accounts. Same happens to picture hosting sites when users close accounts or other changes.

For future DIY posts, please put pictures up as attachments. This way images remain intact for the thread.

 

I have been reading about PS pump leak links that was posted for this thread. I appreciate your input. It seems that the main topic is leading to PS pump leak. I do understand that the vibration of my steering may be related to the PS fluid leak due to bad o-ring.

It seems from everyone's advise that PS leak leads to following areas:
- Hoses to and from the reservoir (this is simple enough to check)
- Screen may be clogged at steering rack solenoid.
- Replace three o-rings (this requires PS pump to be removed).
- Replace or plug up the Air Control Valve.

Among this, what is the villain of power steering purring at low speed in hot temperature, if anyone has direct experience with it. I do not want to remove the PS pump if I don't have to.

Input from anyone with the same symptom, would be appreciated.

 

I don't know about the "purring", but if you have leaking that is causing any spots on the pavement (which is likely to be PS fluid on an LS400, rather than oil) then you better find the leak and fix it fast! - or else you are going to be buying an alternator very soon, if you dilly dally!

● if it is leaking into the intake, you tend to get smoke from the exhaust, rather than a leak on the ground

● if it is leaking on the ground, the $3 o-ring between reservoir and pump is a likely candidate, and the high pressure hose (cheap on ebay), is probably next most likely


as far as a vibration source, my two candidates would be:

● someone let the fluid get too low and damaged the pump to some degree, only a rebuild of the pump (which is not too difficult) will fix that, and the parts need to do this rebuild from Toyota are pretty cheap as well

● the vibration may be something not even related to the PS system - the tranny mount is a likely candidate (another very low cost part, but make sure to use real Toyota parts on all of these fixes, except the high pressure hose, aftermarket omega is fine, or having your hose rebuilt is a good option as well)

 

Thanks for the advice, again. This forum should award you for all of the aid that you are providing to forum members. ECM caps alone, you have saved couple of hundreds of dollars, if not thousands for some member.

As to the steering vibration, I do not think it is the trans mount because for one my gear shifter is not vibrating in idle and this steering vibration only happens when I am turning in slow or almost standing speed. It seems to happen only when both outside temperature and engine is in hot state.

I am not getting any white smoke at cold start nor, have any visible leak on the ground. My LS is parked in the same spot in my garage for last 12 years.

I've had the car since new and this problem of steering vibrating and fluid leak started to happen about 10 years ago. At the beginning of the problem, I replace the PS pump with a used one. This did not fix the steering vibrating problem nor losing fluid. Matter of fact, I still have my old PS pump that I took out then.

I am leaning towards to solenoid screen. This should not be a big deal as I do not have to remove the pump.

If I am experiencing the steering vibration, I am sure someone else is experiencing the same problem. I was hoping to pin point the problem if that person have resolved the problem. Fluid leak may or may not be related to the steering vibration problem but his has to be fixed as well. But I do not think it is affecting the alternator as I've been losing fluid for last 10 years without an alternator problem.

As far as how much fluid I am losing is concern, I am not sure. I do not drive the car in winter and I only put on about 3K to 4K miles per year. I may have to add a half pint a year many be?

 

if you end up having to pull the pump, I recommend you go back to the original pump, which was likely fine if the symptom didn't change, as it sounds like you replaced it with an aftermarket pump, which is not going to be anywhere near the quality of the original Aisin or Nippon Denso pump that you pulled off - just sayin!

 

Cowboy,

I am thinking the same thing. But the old pump is still 20+ years old. I will try to rebuild it on my own to replace if I decided to pull the pump.

The pump that is on the car is OEM. I bought a used OEM pump. Like you, I would not put an after market parts on my LS when it comes to major component like PS pump.

 

The solenoid screen was easy to clean on mine, its on the drivers side, mounted on the rack, you need a thin, sharp punch and hammer to remove and install it, I used varsol and a brush to clean my screen, it helped with my purr/whine quite a bit it its still there somewhat. I think my pump is causing my problem since it overflows from the cap at times.

 

I would get the rebuild kit from Lexus - and then disassemble both pumps (easy) and use the best condition parts of each along with the rebuild kit to make one minty condition pump and that should fix the "purr"