Why is Dexron ATF the de facto hydraulic fluid?

[Thermo1223]

I ask only because PS is a hydraulic system not some automatic transmission with clutches.

So it is sealed(to a point). Now I understand the cleaning abilities of ATF so is that the reason?

I ask because we have a piece of equipment at work that is purely hydraulic and indoors. It is a scissor lift that uses hydraulics to lift and move the unit. It has a very large tank for the system. Inscribed right on top is "Use Dexron ATF III only". I found that curious consider none of our other lift trucks call for that. This unit was filtered as well just as any other.

I am wondering if it is only for ease of obtaining the fluid for dealers/ind/owners that if they speced something like CH11S nobody would bother to change it or use it and then cause problems.

It then got me thinking can I used CH11S if I totally flush the system out? Would the pump/rack even care?

Just thinking out loud.

 

[earlyre]

my guess (and it is just that), is yeah, ease of availability, and b/c it works...

I know my neon's power steering, Specs ATF +4 same as the trans..

 

[01rangerxl]

X2, most likely ease of availability and cost. It's much easier and cheaper to use a fluid that's already widely available that works than it is to come up with a specialty fluid, or try out a variety of specialty fluids.

Maybe the manufacturer has a big account with a rental company or government who prefers a cheap and easy to obtain fluid like Dex.

 

[Silk]

GM practically invented the auto trans, and the fluid that goes with it. Almost everyone who made an auto trans after that used the GM fluid. It works in most other hydraulic systems too, and can be found everywhere oil is sold.

 

[Doog]

Most all Toyota PS systems use DexIII.

 

[Thermo1223]

Ya it must just be from ease of acquiring the fluid. The scissor lift is nothing exotic. The kind you would expect to see in a dept. store for changing lights and such.