WDoherty

Several months ago i added the steering rack replacement as part of my timing service on an sc400. I ended up hurting my back/neck working on the car so i haven't had my car all year after this work. Now i'm doing better and getting back on it and want to solve the problem. The rack was an a1 cardone unit, and I replaced the high pressure hose with a driftmotion unit. The first oem powersteering pump whined after new hose/rack install (pump installed 05), didn't do that with with the original rack, i just had some seeping with the old rack. So did a rebuilt pump, so I don't think the pump is the problem. I also replaced all the return line with 3/8" power steering hose and recently replaced the resevoir with a brand new toyota supra unit because the screen in the old one was deteriorated. Screen on rack solenoid was cleaned and solenoid was tested with 12v, it clicks. Have not tested signal going to it. The entire steering system has been replaced except the metal lines in the return which i purged with shop air. So....
Suspects:
1. Driftmotion line: Too much restriction? I kinda doubt this looking at the diameter of pipe inside stock banjo fittings, but not sure.

2. A1 Cardone rack: The other variable that changed from stock.

3. Two faulty pumps, 2nd was rebuilt unit off Rockauto.com

The whine is very slight, not loud and the feeling of steering is just not right, its like i can feel the vibration of the fluid. There were no bubbles in fluid with old or new resevoir installed.

System was bleed each time a component was off, I've been through about 6-7 quarts of Dex 2 and many times i put fluid back that i had bleed a few times.

I'm really stumped and my car has been down for 6 months!

NjLexSc400

i would also like some clarification on this

i replaced my pump and had a metal line go bad on me in which i had brazed to fix it

my ps tightens up under 1000 rpms

its just weird and confusing.

my splash shield is wet and i add psf after long drives



the big issue is it tightens up under 1000 rpms

WDoherty

I'm probably going to take it to a toy/lex mechanic at this point. I'm in the middle of the desert in Southwest TX. I will probably take it to Elite auto in El Paso or one of the toy/lex shops in Austin and let you know what they find.

WDoherty

If you have fluid coming out, check the banjo bolt connections on the pump and rack, sometime you can't reuse the copper washers and get them to work. I have found the factory washers only to really work for me.

TechGreek

iTrader: (4)

Fluid coming OUT means air is getting IN.

I had issues bleeding my "new" used PS pump and it ended up being one of the hard lines was rubbing and letting air in randomly.

All is fine now with it though after replacing the lines

WDoherty

I just spoke to a toy/lex mechanic I am thinking about taking it too and he thinks I have a reservoir problem. He explain they get clogged and I explained that my old one had the screen gone and I just replaced it with a new one for a toyota supra. He said the flow may be incorrect, the canister is the same, but I can see internally its different. The lexus had a plastic mechanism and all I see in the Toyota unit is the screen, it looks like there is ow flow when running. I'd be really suprised if the flow characteristics of the resevoir between the two models could be so much to cause problems.

P.S.
Just too clarify with the other user posting on this thread, i have no fluid leak.

TechGreek

iTrader: (4)

Lol it's not your res causing insufficient flow. You've got air in the system more than likely.

Do your wheels skip instead of turning smoothly?

WDoherty

Skip, no, but feels like more than normal effort, yes. At highway speed can't hear pump or tell that steering isn't quite right. Jacked up front and turned rack back and forth with pump on to bleed with cap off. No bubbles in resevoir,still think there could be air somewhere?

TechGreek

iTrader: (4)

Mine had zero bubbles when mine was doing what it was doing. If the steering is not skipping the rack is probably ok (usually it'll skip when there are issues from prior experience).

How are you bleeding it? You've got the Supra Res so you might need to jack your car in the air and turn it a lot with the cap off, then let it go for a day or two and see what it does.