Synthetic ATF in Power Steering??

[schnier]

I have some extra synthetic ATF from the Alison and wondered if it would be a good idea to change the power steering fluid and fill it with the synthetic ATF Transynd that I use in the Alison tranny. Any thoughts, is this a good idea, or bad idea? Just curious.

[DmaxMaverick]

I switched out my PS fluid to Amsoil synthetic ATF about the same time I did my tranny. Almost 50K ago. No leaks. No drips. No errors. Much quieter than the OEM fill, and seems to hold pressure/power better under load also.

Flushing the system is a breeze.
Disconnect the return line hose at the brake booster (it's the one with the low pressure spring clamp on it) and place a similar sized hose onto the barb, long enough to reach over the fender and near the ground. Place the end of the new hose into a 1 or 2 gallon container. Make sure that the hose you removed is kept above the level of the PS pump filler, or it will drain out all over the place, or you could plug it.
Start the engine and cycle the steering (lock to lock) and brake pedal until you hear a change in pump sound. If you go off idle, the flow out of the hose may exceed your expectations. Shut off engine and fill the PS reservoir. Repeat until all the old fluid is gone, and the fresh fluid is all that comes out of the hose. I flushed about 2 gallons total to be sure it was complete. Replace the hose to the original position and top off the reservoir. Drive. Be happy.

[Jack's Dmax]

There a couple of things that come to mind about changing your power steering fluid.

1.The potential of a compatibility problem at some time in the future when you need to add fluid while away from home.
2. (Potential Warranty issues)you could be providing an easy way out for a dealer to decline to do repairs under warranty.

Since I am not a Chemical Engineer, these thoughts are just my opinion. I don't actually know what the difference is between ATF and PS fluid.

Good luck with your choice,

Jack

[DmaxMaverick]

GM's recommended alternative to their PS fluid is Dexron III ATF. Replacing mineral based PS fluid with synthetic ATF is an upgrade. The warranty concern is not an issue. Any dealer that says otherwise is really reaching. Some dealers require you use their air freshener or your fuel injectors will not be warranteed.