1995 Lexus SC400 @ 145,000. About two years I had my shop (they've done much work to my car and I've always been very happy) install a new Lexus power steering pump. At the same time I also had my existing rack rebuilt by a very reputable company. A week ago my pump starting squealing. The steering itself is responsive and firm like it always has been. If not for the squealing I wouldn't suspect any issues. I now live in a different state so I had to take it in to a new shop. The mechanic looked at the fluid level and immediately told me I had the wrong power steering fluid in it. I talked to Lexus and they recommended the Redline full synthetic fluid. I had the new shop do a flush/fill with the Redline fluid and the noise is still there but not as bad. The mechanic said to drive it for a couple of days and see if it gets quiet. If it doesn't get quiet then he says I need a new pump. Does everyone agree with this diagnosis/suggestion? Should I be concerned my rack seals have been compromised with the incorrect fluid? Should I be concerned anything else in the power steering system has been compromised with the incorrect fluid? As always thank you very in advance for any and all comments and opinions.

 

The fluid should be a DEXRON 3 auto transmission fluid. I've never heard of a dealership ever recommending a synthetic fluid let alone Redline fluid. I used to work at Toyota in the parts department, and all you need is DEX 3 auto trans fluid. All Toyotas from 1990- today run DEX 3 fluid in the powersteering.

I think that's weird that he said the fluid was the wrong type. Maybe because it wasn't the color red? You can't determine type just by looking at it.
If he isn't familiar with Toyotas then it might be that he's just not familiar with a powersteering system that runs using auto trans fluid instead of powersteering fluid...

Whats the condition of your belt? Is it good? Maybe the squealing you hear is the belt slipping instead of the pump

 

@1997 Soarer,

I know Toyota and Lexus are technically the same. But we are talking about Lexus here and they are very different on many levels. I called three different Lexus dealerships in Vegas and Phoenix and they all said the same thing. They give the customer the option of the Lexus standard fluid or the Redline synthetic. The mechanic immediately said the fluid was wrong because it WAS red. With that being said, I don't know/care where you worked or how long you worked there. DO NOT EVER PUT DOT 3 BRAKE FLUID INTO YOUR POWER STEERING SYSTEM. There is no such thing as DOT 3 ATF. This is just common sense to me. But don't take my word for it, do a Google search and there is a plethora of info as to the why. Here is a good FYI read: https://www.quora.com/Is-power-steer...as-brake-fluid. I do appreciate your response though. OH, I do know the difference between a belt squeal and mechanical squeal.

 

Should be Toyota T-IV atf. The color is red. Never heard of dealers recommend redline fluid either

 

Edited my post to reflect my brain fart. It's not DOT 3 Trans fluid lol. It's DEXRON 3 ATF fluid. We called it Type 3 at the dealership. Toyota also uses Type IV and Type WS fluid. Type IV is what goes in the 5spd auto trans of the 1998+ SC3/400.

At our dealership we never put Type IV fluid in powersteering systems. We always used DEXRON 3. Our bottles looked like what Kahn posted below VVVVV

 

^^ Yep, this is what we're supposed to use. I'm not sure why the Lexus dealers rcgo88 all recommended Redline fluid (which had better be a Dexron III ATF compatible fluid). Seems more like an expensive alternative that isn't really needed but which probably works about the same as the recommended factory fluid.

The only thing I can imagine that would truly differentiate the Redline fluid is if it allows normal operation but with a higher boiling point on a track... which I doubt Lexus dealers are going to have recommended for such a purpose. Also, in those extreme owner use circumstances at least with our SC's (and MKIV's) the solution is to install an auxiliary aftermarket PS cooler/radiator with a small unit designed for ATF fluid. And those folks still use plain old Dexron II/III compatible Toyota ATF.

90's and newer Toyota and Lexus vehicles all use Dexron II or III style ATF for their power steering systems unless specifically noted otherwise. The SC300/400/Soarer, MKIV Supra, GS series, IS, Camrys, etc. all use it instead of common "power steering" fluid.

The Dexron numbers go up through VI now though. The easiest solution? Just get the Toyota T-IV ATF quart bottles. It used to be available in T-III bottles but they updated them and this is what Toyota/Lexus considers backward compatible with any earlier power steering systems that call for Dexron II or III fluid on the caps and in the vintage owner's manuals.

Toyota P/N 00718-ATF00

 

@ 1997 Soarer - I almost thought I was being trolled with the DOT 3 thing. You seem to have a good reputation and to make such a ridiculous suggestion took me aback. Thanx for the update.

Now back to on topic. Now that I have been driving for a couple days, the noise is completely gone. Maybe this can be attributed to the synthetic fluid or the fact the fluid is new and/or maybe I just needed a good flush. Time will tell. I can't say if the old shop used Toyota ATF or an off brand. I'm guessing they used a cheap brand. The Redline I had used for the flush/fill was purchased from Lexus. SO, mechanic recommended clear fluid, several Lexus dealers recommended the Redline, Redline 30404 purchased at Lexus and there are plenty of members on this very site using the Redline. I'm sure the Toyota ATF is very much appropriate but I feel pretty comfortable with using the Redline.

As stated in my original post: Should I be concerned my rack seals have been compromised with the incorrect/cheap fluid? Should I be concerned anything else in the power steering system has been compromised with the incorrect/cheap fluid?

 

That's weird, i've been using Type IV for my car since i've gotten it. I have heard of other dexron 3 fluids that is useable, but i never went down that road got a box of type IV and never looked back.

 

I think you'll be ok now. I'd be more concerned if the noise didn't go away.