What's the best way to drain and change the power steering fluid in my '94 Aerostar with the 3.0l? At 146k, I noticed it looks pretty brown. The pump chatters just like it always has (I've not heard one that didn't), but now the system seems to stick a little when turning the wheels in a bit of a bind (like when I'm turning but not rolling very fast). Thought maybe some fresh fluid would do it some good. Any help is appreciated.

 

[updated:LAST EDITED ON 08-Jan-03 AT 03:38 PM (EST)]Here's a page with some recommendations on how to flush the power steering. http://www.glue.umd.edu/~singletn/web/pages/pspump.html
Read the first article, the fourth paragraph from the bottom discusses flushing the system. The site itself contains lots of good maintenance tips on other topics as well.

Anyway, I've never tried the recommended procedure because I can't always get my lovely assistant to help when needed so I ended up sucking out as much fluid from the reservoir as I could and putting new fluid in. With the front end off the ground, I would start it up and turn the steering wheel from lock to lock to get the new fluid into the system. Then, I repeated the procedure until I had put about two quarts into the system. Probably not as good as the flush, but better than not doing it.

I've thought about a better way to do this by myeslf and came up with the following, but I have yet to try it. Get an extra cap and plug it so no fluid can come out of the top. Remove the return line and extend it so it goes to the bucket. Then, connect a remote reservoir of some sort (made from large diameter PVC pipe, perhaps) with a long clear line (so you can see how low the fluid is getting) to the return port and fill the reservoir up. Then start up the engine and turn the wheel from stop to stop making sure the pump doesn't run dry. Refill and flush till the fluid comes out clean. You don't want to let the pump run dry and get air in the system. I plan on giving this a try in a couple of months, but if you try it before then, let me know how it works.

Another alternative might be to put a tee in the return line and then run a line to a valve, then to the bucket. This way you could regulate to some degree the amount of fluid going to the bucket so you don't drain the reservoir so quickly. Also, with a slower drain rate, you wouldn't need a large remote reservoir.

I'm not sure there is a best way. No matter what you end up doing, I think it will be messy.

 

 

Thanks for the information and the links. Looks like it might be a messy job, but should probably be done. A question on the information in the links however, they recommend filling the power steering pump with ATF. Is this an acceptable substitution? Is there any problem with mixing ATF and power steering fluid? And if not, which ATF should I use? Thanks again.

 

Both my '91 Ranger and '95 Aerostar use Type F ATF in the power steering system. In the back of the owner's manual it should tell you the specification. It's something like M2C33-F. I've used it without any problem and I assume it's what Ford used (instead of "power steering fluid") since they list the Type F spec.