TunedRX300

Tired of power steering pump's whining, I decided to flush as much P/S fluid as possible out of my RX. Replacing what is in the reservior is simple and easy, but with 69588 miles on the original fluid, I want to do more than just incremental replacement.

The whole procedure takes less work than Transmission Fluid, Pan, Filter Change . Took me <30 minutes and no need to get under the car.
Here are the instructions I used along the way w/ pictures. Please feel free to comment if you find an error or find a better way to accomplish the goal.
Again, not that it is likely, I take no responsibility if you (or the P/S) are injured or killed by my DIY instructions.
Step 1: Get tools and part
Part: Any ATF Dexron II or III for P/S fluid. My choice is one quart of Mobil 1 Synthetic ATF ($6.19 from Autozone).
Required tools: 10mm socket (6 point preferred), 10 inch extension bar, wrachet, flat head screw driver, plier (one in RX300's tool bag), small funnel, shop towel, latex gloves, some newspaper, Hydraulic jack, empty 1 quart engine oil bottle.
Optional tools: RX300 service manual

Step 2: Jack Front Wheels Up
Make sure shift pod is at "P", set parking brake, I used the middle of the front frame as a jack point to raise the front wheel. Stop raising the car until both wheels are barely off the ground. If you don't have hydraulic jack, you can use two emergency jacks to support and raise both wheels.

TunedRX300

Step 3: Drain P/S fluid out of reservior
Pop the hood, locate the power steering reservior on the passenger side. Uncap it. Place newspaper under the ground just below the P/S pulley

Trace the down hose you will see a 10mm bolt hold the P/S pressure line next to the crank pulley, un-bolt it with wrachet and 10mm socket on the 10" extension to make room for manuveur

Place some shop towel under the hose (smaller diametered one) you are about to disconnect, loosen two spring clamps on the down hose with plier and move them off connecting ends. There is one clamp on the reservior end and one the P/S metal pressure line end.

Use screw driver to pry the hose off the reservior. Catch the P/S fluid with empty engine oil bottle or shop towel. Let the bottom spring clamp slide on the metal P/S line. You need to wingle the hose and the pressure line a little to turn the hose pointing to the front of the car.

Step 4: Wear google or glasses to protect your eyes. Place the open end of repositioned hose inside your collecting bottle, be sure not to interfer with P/S belt. Ask another helper to start the car while you make sure P/S fluid will be pumped into the bottle. Ask your helper to make several turn to turn and hold the steering wheel for 2-3 seconds at the end of each turn, all while the engine is running idle. It takes about 1-2 minutes to get all fluids out. Stop the engine
Lexus service manual calls for engine running when bleeding air out, so I was comfortable to let P/S pump to operate 1-2 minutes with air in the fluid.
Note: P/S pump draws from the bottom of the reservior and returns fluid from the top pressure line.

TunedRX300

Step 5: With engine off, wipe off excessive spills. Reconnect P/S hose to the reservior and the P/S pressure line. Put both clamps back. Place the funnel on the reservior and fill the reservior to "cold max" mark. Ask your helper to start the car, as the pump starts to circulates fluid, check for leaks, then slowly pour more fresh fluid into the funnel. Monitor the level, don't add beyond "cold max" mark. Stop adding fluid when the fluid level no longer goes down. I used 1 quart of M1 ATF.

Last Step: With engine still runnin idle, ask your helper to make several turn to turn, holding the steering wheel 2-3 second at the end of the turn. Bubbles will foam ATF you just poured in, stop the engine when there is no more air to be bled out. Lower the car, double check for leaks and spills, put the 10mm bolt back, then test drive.
For me, no more whining from the pump Lexus is charging $110 for the same service but with mineral based fluid. Don't you just love saving those hard earned $?

Lexmex

Mobil 1 ATF is pure gold for the PSF system. I had a few more friends in Mexico switch to this stuff from their OEM fluids and they are already giving it good raves to their friends.

When the PSF fluid gets old, I have noticed it the steering gets a little complacent or it hops (kind of like a slipping transmission). I thought it was one of the suspension arms messed up, but turns out with my old Valvoline synthetic, even when that gets old, there can be issues.

The fact that the parts manager at one of the Toyota dealers down here figured this out even before I told him (they use the Mobil 1 ATF for the PSF) really impressed me.

bob2200

I call everybody's attention to what appears to be an improved technique I found, by search, on the ES300 forum:

https://www.clublexus.com/forums/sho...d.php?t=230152

Thanks ontoy and tunedRX300

TunedRX300

I like the way he uses spary bottle to pump P/S fluid from the reservior. The clear tube is a good idea, but it will be better if tube is placed on the driver side. You can then see P/S fluid and make it a one man job.
No need to plug the outlet hole on the P/S reservior since no fluid is returned during bleeding. If one is worried about a few droplets dripping out, it is easier and more cost effective just wrap a shop towel around the opening.

Fern

Just curious if anyone has used Amsoil atf for the power steering flush?

Don't want to have issues like LEXMEX did with the Valvoline synthetic.

TunedRX300

Fern,
You can give it a try but most people, including me, pick Mobil because it is less expensive and more widely accessible. Can't comment on Vavoline but Mobil 1 experience is a pretty good so far for me.

cerritos

Since you disconnected the top line (according to the picture), if the P/S pump draws fluid from the top line, how can the fluid come out of it?

Maybe it draws from the bottom line and returns via the top line?

TunedRX300

Yes to prevent air from entering the PS pump when fluid level is low.

Bobk528

About three months ago, I used a oil extractor to remove the old fluid from the power steering container, added Mobil 1 synthetic ATF Multi-Vehicle Formula and called it good without turning on the engine and turning the wheel from side to side. It is now making this howling sound that is particularly irritating to hear in the early morning.

I later read this excellent DIY by TUNEDRX300. If I jack up the front end, extract out the fluid, add new Mobil 1 ATF, and turn the wheel from one side to the other end as described above by TUNEDRX300, will this likely resolve the power steering noise issue? I assume the noise is caused by the need to bleed the air out of the system?

chenxingha

Bob2000: The pictures are no longer there.

bob2200

Yes, the pictures weren't mine. Sorry. Basically, he put a plugged-up hose over the barb on the container and mated a long transparent hose to the black hose that was connected to the barb. The fluid was routed from the long transparent hose to a collection container. That's basically all the pictures showed.

TunedRX300

The noise is likely caused by a loosened belt connecting the pulley, AC, and alternator. I have another photo DIY thread, which is now included in the sticky thread.
Another thing you can do is to change oil to a better flowing one, after I changed Mobile1 5w-30 EP to German Castrol, the belt sqeek noise is 90% gone, which might indicate more power is avaliable to turn the pulley before slippery occurs.

philly777

Hello,

Thank you for the excellent write up!!!
Could you please let me know which exactly hose need to be unbolted? Do you have a picture of that 10mm bolt that holds the P/S pressure line?

Thank you!