I have a 1991 ls400. The power steering is atrocious. I continually have to add atf fluid or stop leak into the power steering chamber. I assume it's a leak--a very small one. Any ideas on what stop gap measures to take other than the ones I've already tried

You can get a dye to put in the power steering reservoir it makes the fluid glow

Yes, ATF is fine. You can put that in your power steering altho they make regular power steering fluid too.
You can't put ps fluid in a transmission.

Section 11-00: Steering System-Service 1999 Taurus, Sable Workshop Manual SERVICE PROCEDURES Purging Power Steering System of Air NOTE: If the air is not purged from the power steering system correctly, a second customer concern or pump failure could result. This condition can only occur on pre-delivery vehicles with evidence of aerated fluid or vehicles that have had steering component repair.

A whine noise heard from the power steering pump may be caused by air in the system. The following procedure must be performed whenever any of the following are performed:

• All power steering noise complaints with evidence of aerated fluid on pre-delivery vehicles only, prior to any component repair.
• After any power steering system component (for example, gear or hose) has been replaced and the noise is heard.

Fluid Level Top-Off Procedure

1. Check and fill pump reservoir to dipstick full cold or remote reservoir center mark.
   

1. Disable ignition by removing Fuse 10 in the fuse junction panel.
   

1. Crank engine 30 seconds, check fluid level and add if required.
   

1. NOTE: Do not hold steering wheel on stops.
   
   Crank engine 30 seconds while cycling the steering wheel lock to lock.
   

1. Check fluid level and add fluid if required.
   

Air Purge with Vacuum External Source Procedure - 3.0L (2V) Engine, Flex Fuel and 3.4L SHO Engine

1. Tightly insert the rubber stopper of the air evacuator assembly into pump reservoir.
   

1. Reinstall Fuse 10 used to disable ignition and start vehicle.
   

1. Apply 20-25 in-Hg (85-88 kPa) maximum vacuum for minimum of three minutes at idle; maintain maximum vacuum with vacuum source.
   

1. Release vacuum and remove vacuum source.
   

1. Add fluid to full warm or reservoir center mark.
   

1. Reinstall vacuum source and apply 20-25 in-Hg (85-88 kPa) vacuum.
   

1. NOTE: Do not hold steering wheel on stops.
   
   Cycle steering wheel from lock to lock every 30 seconds for approximately 5 minutes.
   

1. Shut engine off, release vacuum and remove vacuum source.
   

1. Add Motorcraft MERCON Multi-Purpose (ATF) Transmission Fluid if necessary and install dipstick or reservoir cap.
   

1. NOTE: Do not hold steering wheel on stops.
   
   Start engine and cycle steering wheel from lock to lock every 30 seconds for approximately 5 minutes.
   

1. Check for oil leaks at all connections.
   

1. In severe cases it may be necessary to repeat air purge with vacuum source procedure.
   

Air Purge with Vacuum External Source Procedure - 3.0L (2V) and 3.0L (4V)

1. Add Motorcraft MERCON® Multi-purpose (ATF) Transmission Fluid XT-2-QDX or MERCON® equivalent to approximately 2.5 cm (1 in) (make a mark) above the top of the supply line.
   

1. Tightly insert the rubber stopper of the air evacuator assembly into the pump reservoir.
   

1. Apply 85-88 kPa (20-25 in-Hg) maximum vacuum for a minimum of three minutes.
   

1. Add Motorcraft MERCON® Multi-purpose (ATF) Transmission Fluid XT-2-QDX or MERCON® equivalent until the level is at the marked point.
   

1. Repeat Steps 3 and 4 until the fluid level stabilizes.
   

1. Check reservoir level and add Motorcraft MERCON® Multi-purpose (ATF) Transmission Fluid XT-2-QDX or MERCON® equivalent to the FULL WARM (MAX) mark.
   

1. Install the number 10 fuse in the fuse junction panel. Start the engine.
   

1. NOTE: The front wheels must be off the floor during lock-to-lock rotation of the steering wheel.
   
   NOTE: Do not hold the steering wheel on stops.
   
   Reinstall the vacuum source and apply 85-88 kPa (20-25 in-Hg) maximum vacuum and cycle the steering wheel from lock-to-lock every thirty seconds for a minimum of 5 minutes.
   

1. Shut the engine off, release the vacuum and remove the vacuum source.
   

1. Add Motorcraft MERCON® Multi-purpose (ATF) Transmission Fluid XT-2-QDX or MERCON® equivalent to the FULL WARM (MAX) level. Install the dipstick or reservoir cap.
   

1. NOTE: Do not hold the steering wheel on stops.
   
   NOTE: In severe cases, it may be necessary to repeat air purge with vacuum source procedure.
   
   Start the engine and cycle the steering wheel from lock-to-lock every thirty seconds for approximately five minutes.
   

1. Lower the vehicle front end.
   

1. Check for oil leaks at all connections.
   

The main purpose on an alternator is to recharge current back to the battery. One of the most common problems with the Lexus LS400 and SC400 is that power steering pump seal leak. Right below the power steering pump is the alternator. The power steering fluid will drip down and cause many electrical problems for the alternator. Therefore, its very common to have the alternator go bad along with the power steering pump, just be sure to check.

bmw uses ATF as power steering fluid most likely one of the hoses are failing and will need to be replaced if u start to hear a buzzing noise when turning try not to drive vehicle that can burn out the pump but add fluid before you drive it again the resovor is a dark brown or black round canister with a black lid check the fluid in that if its low then you know its the power steering leak if not then it could be a trans. fluid leak if u have a automatic hope this helps you

YOU MUST TOP OFF TO THE FULL LEVEL..

As mentioned check ps fluid. If it wines when turning and still no power then the pump is internally bad.. If the fluid is dissapearing fast then its a hose or most likely a leaking rack& pinion assembly..

Yes Mistydogg, the solution posted here is absolutely correct. And be sure to remove (as much as possible) of the factory power steering fluid from the reservoir and replace with automatic transmission fluid (ATF). Do this a few times during regular oil changing intervals to cycle-out the original factory fluid. The 1995 Camry was shipped from the factory with clear/typical power steering fluid, however (strangely) the factory service manual calls for replacing with automatic steering fluid. Well, it's actually not so strange. ATF has a seal swelling effect that will stop the leaking within your entire power steering system - fast. I ran into the same problem in a big way. The dealer wanted to replace my pump and rack at 50k miles at the remanufactured parts plus labor price of $1,200. I am leak-free today on my same pump and rack at 241k miles having switched over to ATF. Enjoy your great car!

well, i have the same problem. if it is not a large leak, i would continually monitor the level and add fluid as needed(atf fluid). But ideally the hose should either be "pathched" though not advised, or replaced.

sorry that you too have this problem!
I hope that you find this helpful!

Is the belt on the power steering pump tight or loose does the pump makes a huming noise when turning steering all these are causes of hard to turn steering belt need to be (tight) on pump and pump must not be huming when turning steering add fluid if needed and play with steering to see if help if not need to replace pump