bz123

i just bought a 1995 Lexus ls 400 with a leaking steering pump. I replaced the hoses and narrowed down the leak to the air control valve i welded the valve shut and added Teflon tape to the threads.The steering fluid level is stable now but when im driving the pump starts to whine after 10-15 min of driving.The whine is most pronounced when im at a stand still and try to turn the car.please help me out ive been struggling with this for 2 weeks now

oldskewel

iTrader: (1)

I don't know if the '95's still had the filter on the steering rack solenoid, but at least on the Gen1 cars, that was a known problem area. And I'd actually say I think it is the root cause of almost all PS problems on those cars.

If yours has that filter (probably a sticky on here for PS problems), I'd open it up, clean it out and reinstall (they don't sell replacements - it just comes with the solenoid for about $900).

Also on your problem, is the PS affected, other than the noise? Is the noise constant or just when you need PS pressure? If you are able to give it some gas to get the RPMs up, does the problem go away? BTW, that's exactly what the air valve was supposed to do (increase RPM).

timmy0tool

iTrader: (7)

noise usually means lack of lubrication or air in the system.
when you added more PS fluid, did you use the right stuff (DEX III ATF)?
also with the engine on, move the wheel lock to lock a few times to push fluid throughout the system and self bleed.

PureDrifter

iTrader: (10)

Did you bleed the system thoroughly after doing the work? Timmy's got the instructions above.

If the pump was run dry or overly low of fluid it's very possible the internals are toast and you need to replace it.