Best power steering fluid to quiet fussy pump

[dfarr67]

Still searching but wanted some opinions on what has worked for you. My issue is a rpm related pump whine when hot. Will throw some Lubegaurd additive at it for now then change fluid then change pump in that order- have had this or that issue with my system for years. 89 chev k1500 Saginaw with hydroboost, trans cooler on this system. I am using a u-joint vs rag joint so that will contribute to some noise. I have thrown many pumps at this issue and am considering a good used GM unit now.

Lived in northern Canada where keeping PS systems and hoses happy is a challenge- found Acura fluid worked very well.
- on a dyno tuning session the M1 ATF blew out the pump pressure cap, what a mess.
- Amsoil swelled cap seal
- using Redline (with some Ford friction modifier) now with a above mentioned whine.

Looking at a fluid I can buy by the liter or jug some of which are hard to source here.
- LiquiMoly
- Driven
- CHF 202, I have had good luck with Pentosin products in the Honda manual trans.
- CHF 11S
- Febi/Bilstein (part number?)
- Idemitsu (not liter size)
- Ford XT-5
- Lubegaurd seems overly expensive even compared to the above.

I think your seeing a German trend here;) So....I welcome your thoughts.

[Schurkey]

The PS on my Trailblazer whined like a two-year-old.

Instantly fixed with GM "Cold Climate" PS fluid. Of course, this was in the Frozen Wastelands, in winter.

[RCJ]

On our dirt late model you could not use over the counter p/s fluid. I used racing fluid from Sweet. It was noticeablely thicker. After a little research I tried 68 hydraulic fluid, it worked as good as racing fluid.

[rebelrouser]

Lucas oil power steering stop leak fluid, it does wonders. Never seen it really stop a leak, but it is nice and thick and makes them quiet.

[Walter R. Malik]

I bought 5 gallons of CASE synthetic hydraulic oil at Tractor Supply and never encountered an issue in any racing power steering system.

[dfarr67]

Well, came around full circle and did a flush with Beck Arnley Honda fluid and one bottle of Lubeguard. Still get an odd growl but nothing like before. Seems like this is an old trick.

[econo racer]

Lucas from walmart does well for me.

[mt-engines]

AW 32 or 46. unless you are driving in +100 degree weather AW68 is pretty thick. I use 46 mostly. It will quiet down any pump without a severe mechanical problem or air leak. Plus its like $13 a gallon

If I remember correctly AW32 is 10wt, AW46 is 20 wt, and AW68 is 30 wt.

[MT Jeff]

You might try an anti foaming additive. Mopar has one for auto trans fluid. PN 4549637. Not sure if the Lubeguard has an anti foam additive but entrapped air will make a pump noisy. And it's only a couple of bucks.