1999 LS400 With NO power steering AT ALL after series of events.

The car started leaking PS fluid many months ago. It was gradual and manageable until about one month ago when the leaking got more severe. The car was recently given to me by my father. He had been putting Power Steering fluid in it to top off when it would get low. He lost the owners manual and I had no idea it was supposed to be ATF instead of PS fluid until diving into this repair.





Symptoms before partial PS pump seal replacement:
-Leaving large puddles on driveway
-When fluid would get low, the pump would make noises
-The power steering ALWAYS WORKED, however. Never cut out.




It got to the point that I decided to start figuring this out. Found that it was leaking from the reservoir cap, hoses from the reservoir and the notorious o-ring inside the pump on the main send hose nipple from the reservoir. I decided to replace the hoses, cap and put new o-rings in the pump. I did not remove the main parts of the pump meaning the bearings and everything inside, just the other o-rings. Put the pump back together and reinstalled. Filled the system with ATF this time and attempted to bleed the system.



Here are the symptoms currently:
-NO power steering AT ALL, EVER. Not with high revs, not while driving. NOTHING
-No more bubbles come up in the reservoir when trying to bleed (I think it's bled)
-The pump does not make noise anymore




I am about to check the solenoid for blockage and that it is still clicking. I have read all the forums with PS issues and none of them seem to make sense for my car. Before doing anything, everything worked all the time--it just leaked. Afterward, it doesn't work AT ALL. For the ACV, the PS control module, the solenoid (any one of them or a combination) to fail right now seems to be too coincidental for me to believe. I should add that I cracked open one of the brake line style lines on the rack to make sure the ATF did in fact make it through the system and it has.

Is it possible for the valve thing with the spring (that goes inside the high pressure bolt) to be reinstalled in a wrong direction that would inhibit flow of fluid? Could the switch of fluids cause any of these failures to happen? I'm really stumped here so any logical insight or thoughts would be greatly appreciated! PLEASE HELP! Thank you

 

Jack up the front end to take the weight off of the tires. Turn the steering wheel lock to lock several times with the engine running. After several cycles, you should begin to hear the pump strain when you hold the wheel at both lock positions for a few seconds. When it finally purges all the air bubbles, everything should feel smooth. The PS system does not require Toyota ATF; regular PS fluid is fine.

 

fixmiester, unless I am seriously missing something I have done the lock-to-lock thing with the wheels on the ground, wheels in the air, car on, car off, bubbles came out and then stopped coming out and I have had absolutely no luck with any of it.

 

👍 I use regular PS fluid!

On to the no power issue. There is a little valve in between the high pressure line and pump. If you used "STOP LEAK" fluid in your PS system that can cause the valve to get stuck causing no power. I seen it happen to a number of LS400 I worked on. You can take out the valve and clean it.

OR do what fixmeister said but at each full lock HOLD it longer causing more liquid flow/pressure and rev up the engine at the same time. Sometimes it will give enough fluid flow to break free the valve.

 

I'll see if I can find a picture of the valve when I get to a computer

 

what kind of hose did you use to replace the old stuff? i am thinking that the new hose is collapsing and inhibiting flow. what hose did you replace? feed or return or both?

also i believe we are to use DEX III ATF in our PS system. only time will tell if what your dad did putting PS fluid in there will cause problems.

 

Long shot since this thread is 11 years old, but did you ever figure out what was wrong? I'm experiencing this same issue and it's driving me nuts! I cannot figure out for the life of me what went wrong. Rebuilt my OEM pump using the OEM rebuild kit. Everything seems to be working fine when the front wheels are off the ground, but when I go to drive it I've got nothing at all. Someone please help before I light my Celsior on fire!!