Question about power steering fluid

[peterf1992]

well i changed my ps fluid last year june and used prestone power steering fluid and haven't had any problems and this on a 96 taurus ohv with 267,000 miles with the stock power steering pump.

[fct]

The 1999 owner manual recommend Mercon ATF, and later Ford announced that Mercon V ATF replaced Mercon in all previous applications. I put Mercon V in mine. I usually freshen power steering a few times once a year, using a fish tank hose to extract the old fluid. This is kind of a pain considering the power steering container holds just about 1/5th of a quart of fluid.

[SoNic67]

Originally Posted by peterf1992

well i changed my ps fluid last year june and used prestone power steering fluid and haven't had any problems and this on a 96 taurus ohv with 267,000 miles with the stock power steering pump.

When you will have to replace the pump or/and steering rack you will realize how expensive is this experiment.

PS: I don't get why some people don't read the owner manual before changing the fluids. Mercon ATF cost is the same as the generic Prestone PS fluid.
Why they still have PS fluid on shelf? Because other cars use it - like my wife's 2000 Hyundai Sonata.

[Jeff K]

^^^^^ +1000

Get that PS fluid stuff completely out of there ASAP and replace it with the specified Mercon V. Having a shop replace the rack and pump due to using the wrong fluid will cost HUGE $$$$$$.

The owners manual: The little book that everyone has and no one reads.

[Kestas]

I think you guys are overreacting. I'm guessing the vehicle specifies Mercon, as it does for my 2001 model, and not Mercon V. I'm also guessing the reason for that is because that fluid is what is available on the dealer shelf without having to stock extra or special fluids. This is how companies think. I doubt the system is that sensitive to fluid type.

[sheila]

Fwiw, all fluid applications that once called for mercon/dexron3 atf have been backspec'd to use mercon v atf. Does not incude the old Ford type F atf applications.

[SloppyJalopey]

Mercon V was engineered to mix with and replace Mercon.

[SoNic67]

There is still Mercon on shelves, that is not an issue if you don't want to use the better Mercon V:
Castrol Domestic Multi-Vehicle Automatic Transmission Fluid, 1 qt: Automotive : Walmart.com

[fct]

Walmart also introduced its own brand of Mercon V fluid. It's called Supertech Mercon V. It's probably the cheapest Mercon V fluid available. I wouldn't put it down considering W-M Supertech is just a rebranded fluid made by major refiners, such as Exxon/Mobil. This is what I'd use as PS fluid, maybe for ATF application too (but I have a case of Motorcraft sitting on a shelf).

[JohnSawyer]

As I understand it (based on reading various online threads for the past couple years, mostly here on taurusclub--someone correct me if I'm wrong), a few (or just a couple?) years ago, Ford finally decided that Mercon V was OK to use even in Taurus Gen 1 and Gen 2 transmissions that originally called for Type F. Because of this change in recommendation on ATF, I assume (?) that Mercon V is also OK to use as power steering fluid in these older Tauruses, even though Ford originally spec'd Type F for their power steering fluid too. The original dire warnings from Ford about using Mercon V in their older, formerly Type F-only transmissions, were apparently due to some of these older transmissions failing after people put Mercon V into them, but these transmissions were old enough to have problems that were the actual causes for their failure, rather than the Mercon V. Also, some fluid changing outfits were using the "power flush" technique which some older transmissions can't handle.

So instead of using a power flush (with any ATF, not just Mercon V), the recommendation here has been to do the simpler pumpout approach using the car's ATF pump, directing the output of the pump into a container, starting up the engine, and quickly pouring new ATF into the fill tube until just that new fluid comes out, making sure to keep up with the fluid pumpout rate so that the transmission doesn't go dry during the process. I did this a couple years ago, though I refilled with a new synthetic Dexron III/Mercon (made by Eneos) instead of Mercon V just because I wanted to see how the Eneos would behave in my 1994's AX4S--I was hoping it might improve acceleration and reduce some clunking the transmission had been doing for some time. It did improve these problems, but not as much as I wanted, so I poured in some Lucas Transmission Fix a while later to see if that would help further, but that stuff is so thick that it made the symptoms much worse. To try to fix the worsened symptoms, I pumped out three quarts of that mess and replaced it with Mobil 1 Multi-Purpose ATF (spec'd for Dexron III/Mercon/Mercon V use), which improved the symptoms almost back to the pre-Lucas state, but soon I'll be replacing the remaining Lucas-infected Eneos with nothing but Mercon V, and I'll probably be fine.