Anyone ever use ATF fluid in place of PS fluid?

[mrvax]

Just took the car in for an oil change. The young mechanic saw the power steering fluid was reddish and suggested having the PS system drained, cleaned and refilled ($70).

He was confused when I told him I used automatic transmission fluid in there in place of power steering fluid. I've done this all my life (46 years) and never had a problem with any car's PS.

Anyone know of anybody that had trouble with the power steering after doing this?

Thanks.

 

[RandyStinchcomb]

its all the same wth 1 exception, early model Fords used type "F" and now they use Mercon III or Mercon V, its all hydraulic fluid, same **** just different names.

one side note:
some of the newer Fords, like 1999 up can get air-bound in the P/S system after changing a pump, rack or just changing the fluid and if this happens, except a real mess as it may take a day (or 2) to purge the sysyem of air.

 

[saleen409]

I thought that's what everybody used years and years ago... (30 to 40 years). lol

 

[mrvax]

Thanks, gents.

 

[LaserRed01GT]

You are supposed to use Mercon ATF. The owner's manual, service manuals, and even Alldata specifically say to only use Mercon ATF...and for good reason.

ATF has a unique additive package that regular PS fluid does not. Just a few of the things that the ATF additive package contains is dispersants, antioxidants, friction modifiers, corrosion inhibitor, seal swell agent, and viscosity improvers, and a foam inhibitors. Conventional PS fluid has a much different chemistry. ATF also has a much better low temp fluidity property that is easy on the valve assembly until it warms up.

Our power steering system was designed to use ATF and only ATF. The pump seals and rack seals are specifically designed to work with ATF, not conventional PS fluid. If you use conventional PS fluid, you stand the chance of a failed seal/o-ring and/or pump and valve assembly problems.

Only use Mercon ATF in your power steering resevoir. You had it right the first time.

 

[Saleen4971]

^ im with him. only mercon ATF. mine is filled with redline synthetic.

oh - and its not just the power steering, hydroboost uses PS pressure as well!!