Is it okay to mix different types of dexron ATF in my power steering? (2 Viewers)

[psilocyBen]

I’ve been trying to fix my power steering whine and have had zero luck. The whine is getting worse and I’m beginning to feel the steering wheel become hard to turn. First I tried flushing by draining the reservoir, adding Dexron iii, turning wheels lock to lock, and repeating the process til it was clear red. That did nothing. Next I placed the entire reservoir hoping the filter was clogged. That did nothing. I tried doing a proper flush this time by emptying from the return line but my return line attachment snapped, spraying fluid everywhere and out of frustration I just reattached it and tried flushing it the first way (by draining reservoir, turning wheels, and adding new fluid a few times).

Now the problem seems worse and I’m tripping out that I mixed Oreillys brand Dexron III with Valvoline Maxlife ATF. Is there any adverse effects of having both of these fluids mixed in my power steering system? Is it just time for a new pump? I don’t think I have a leak since the fluid level in the reservoir is staying exactly the same. Any insight here greatly appreciated.

 

[ninety7lx450]

There was a lengthy post about the types of dexron:

Dexron III ATF

What's a good Dexron III ATF to put in my LX this days? M1 doesn't seem to make any this days other than Mobil 1 Synthetic ATF. Can I put synthetic in this rig with 120k on it? Serge

forum.ih8mud.com

Did you get this problem fixed? (Im got a similar issue on my LX)

 

[SteveH]

All reputable fluids that are Dexron III compatible are fine. I would not mix or use Dex IV. Try jacking up the front end of your Lexus and cycling the steering back and forth with the engine off (not running). This works on some vehicles and is required on some. Whining is typically a worn pump sound. You can also add a small amount (4 oz) of Lucas Power Steering stuff (whatever it's called - $12.99 at O'Reillys). It will often quiet a loud, older system.