How-To: Transmission flush and filter replacement

I recently braved the transmission flush procedure on my 2000 Windstar. Windstar transmissions are notoriously weak and fail without extra-special babying. The Ford factory recommendation for filter and fluid changes in the Windstar is 30k miles or 21k for 'severe service' (taxi driving, city driving, short trips). Wiswind has a great how-to on how to drop the pan and change the filter (link below). While this is great for your vehicle, some (like mine, bought used) have not had conscientious service done to the trans. In my case, it's been over 60k miles since the last service, and it's on it's third Ford transmission (wasn't me, long story). Anyway, I wanted to see the condition of the transmission by checking the condition of the fluid and the ferrous particles on the pan magnet, as well as remove ALL of the old fluid. Doing this flush is really the only way for an owner to get all of the old fluid out, since the total system capacity is 11.6 liters (12.3 quarts), and the pan drop procedure only gets out about 7-7.5 quarts (the rest stays in the torque convertor which has no drain plug). You could go to the stealership and have them hook up the backflush machine that uses heated fluid, but I've read that this is not good. Plus, it's the stealership! We're DIY people.

Things you'll need:
- 3-ton ramps/3-ton jack & jackstands/vehicle lift
- lots of rags (this can get messy)
- 8mm socket set (for pan bolts)
- flat-head screwdriver
- 15 quarts Mercon V A/T fluid
- tall funnel
- 19.5"x11.5" foil pan (usually sold as a pasta pan)
- bucket to catch fluid (helpful to have it graduated in quarts)
- 3/8" I.D. clear tubing
- tube clamps/3/8" i.d. hose barbs to connect tubing
- assortment of vacuum plugs
- A/T filter
- spray can of Seafoam Deep Creep or P'Blaster
- Magnetic A/T filter (optional)
- hand-operated fluid pump (optional)

The Ford procedure assumes that you won't change the filter but just flush. I'm doing both here, hence the added filter. Your call.

Get the front of the vehicle off the ground (safety first!!!), and locate the cooler feed and return lines under the DRIVER'S side of the van. The line you want to remove is the BOTTOM one (the return line).(http://good-times.webshots.com/photo/2372229270101767595LcSYKf) That line has probably been in there since the van rolled off of the line in Canada, so it's crudded up and stuck in there. To loosen the connection and make it easier to remove, spray down the bottom connection with the Deep Creep or P'Blaster (I used the latter), and let it sit for 5-10 min. while you do other things like set up your foil pan for draining and cut your tubing to go into your bucket. I used my power steering flush kit, which is the same 3/8" i.d. tubing. (http://good-times.webshots.com/photo/2226748760101767595nbcCNk) I clamped it onto the end of the cooler return line. (http://good-times.webshots.com/photo/2127727870101767595DJFItL) I also took the vacuum plug from my P/S flush kit to plug the cooler return port. It was too big to fit, so I went with the next smallest plug in my kit. (http://good-times.webshots.com/photo/2776639530101767595lBVrat)

My van had a Motorcraft magnetic inline filter installed in the feed line before the cooler. Dealers typically do this when a transmission fails, to catch ferrous particles from the new trans and anything left in the cooler lines that can get through the system. It's a good idea to do, but this caused me problems and extra time, because I assumed that I could remove the filter from its housing for the flush (you don't want it in place while flushing). I had to get some hose barbs to fill the gap of hose left when the filter was removed. (http://good-times.webshots.com/photo/2062623080101767595dWOZLN) (http://good-times.webshots.com/photo/2946148460101767595Hyylip)

Once it was all in place, the hoses connected and tight, and the overflow hose going to my measured bucket, I had my daughter start the van while I watched the fluid flow into the bucket. Once the flow starts to sputter and bubble, the trans fluid pump is starting to cavitate. Stop the engine to avoid burning out the pump. This gets out about 3 quarts. There are still around 3.5 quarts left in the pan at this point, so I took my fluid pump to get out as much as possible. Pumping out the pan this way got about 6.5 qts. (http://good-times.webshots.com/photo/2308646100101767595pjIpOE) and left as little as possible in the pan to avoid a mess. Again, your call. I got my pump at Harbor Freight; I've seen them elsewhere like Pep Boys. There is probably a little over a quart left in the pan, so that foil pasta pan comes in handy here.

I then loosened the pan bolts one at a time, taking care to loosen the rear end more (remember that the front end is elevated) to make the fluid go toward my catch pan. Don't take forever loosening a little at a time like I did; not much comes out at first. Get all the bolts out and hold that pan against the flange until you can lower it evenly. Some sloshed out anyway, which made a bit of a mess.

From there, wipe down the pan, magnet and gasket. Remember that the gasket is reusable, so don't force it off of the flange or pan and break it. Pull off the old filter, then turn it over and drain it into your pan. Wipe down the internals that were under the pan gently, and thoroughly clean the pan mating surface. Pull the old filter neck gasket from the hole, and install the new filter in the same way as the old one. Then install your now-clean gasket and pan,(http://good-times.webshots.com/photo/2036173660101767595jUmbMS) hand-tightening the bolts first, then gradually tightening in a criss-cross pattern to 8 ft. lbs. (which is securely hand-tight with one hand turning the ratchet). This minimizes the chance for leaks and bending the flange of the pan.

Fill what you removed (I added 7 qts. here), pump out another 3, fill another 3, pump another 4 and fill 4. You're now done with the fluid, but we have to reconnect everything. Remove the vacuum plug from the trans, pull the tubing off of the return line and reconnect the line to the trans. Push it in to a click, pull back slightly to make sure it's seated, then reinstall the retaining clip. If you had an inline filter, pull the tubing off of there too and remove the hose barbs by twisting and pulling them straight out with pliers (don't ask me how I figured this out...). Reinstall the magnetic filter and clamp the hoses to it securely.

Now start the van and let it run, and go back underneath and check every connection for leaks. Sit there for a few minutes and be patient. If you've done your job well, nothing will leak. Let it warm up for a bit, then check the level. Hopefully you saved that last quart for topping off the level. Enjoy your van's new lease on life!

Helpful threads:
- Wiswind's pan drop procedure in pictures: http://rides.webshots.com/photo/1503284711011220610kYSGCI
- http://www.automotiveforums.com/vbulletin/showthread.php?t=501284
- http://www.automotiveforums.com/vbulletin/showthread.php?t=739229
- http://www.automotiveforums.com/vbulletin/showthread.php?t=952333
- http://www.automotiveforums.com/vbulletin/showthread.php?t=902381
- http://www.automotiveforums.com/vbulletin/showthread.php?t=625072
- This guy cut open his Magnefine filter: http://www.v6performance.net/forums/6g-performance-discussion/60257-cut-open-magnefine-transmission-filter-pics.html

Great! Thanks for the procedure, I'm pretty sure it will help MANY other users from now and on. It would be great if wiswind could make it a 'sticky' so it appears always at the top of the forum.

On the other hand I did this same procedure today it took me 4 hrs (first time I´ve ever done it on my own) taking my time. I don't know why but the fluid was completely dark, it looked like mud, fluid only had 5k kms on it (I'm thinking the guy who "fixed" it likes to "keep" his customers). Anyway now the van runs great again but I found a funny thing I don't know why when I removed the bottom line and started the engine I was waiting for fluid to start coming out of the extension hose and then I realized fluid was coming out of the transmission! So I cleaned everything, plugged back in the line and unplugged the TOP line, this was the correct one and when I started the engine after a few seconds fluid started to come out of it.

It's weird, everyone else uses the bottom line; any comments about it?

Regards,

Oscar.

On the other hand I did this same procedure today it took me 4 hrs (first time I´ve ever done it on my own) taking my time. I don't know why but the fluid was completely dark, it looked like mud, fluid only had 5k kms on it (I'm thinking the guy who "fixed" it likes to "keep" his customers). Anyway now the van runs great again but I found a funny thing I don't know why when I removed the bottom line and started the engine I was waiting for fluid to start coming out of the extension hose and then I realized fluid was coming out of the transmission! So I cleaned everything, plugged back in the line and unplugged the TOP line, this was the correct one and when I started the engine after a few seconds fluid started to come out of it.

It's weird, everyone else uses the bottom line; any comments about it?

That is extremely odd. The only thing I can think of is, when you saw fluid from the trans, it's because you didn't have the hole where the line came from plugged, so it flowed out. The top line is the feed line (that's what I call it), that feeds fluid to the cooler, then it comes out of the cooler and back into the trans from the bottom line. I have no idea why yours worked the way it did. Your van is a 2000 like mine. I am stumped. Someone smarter than me needs to chime in here.

Yeah tell me about it!

When I said fluid was coming out, I meant to say it was actually squirting fluid out of the transmission and not just dripping. After about 15 seconds fluid NEVER came out of the hose. was until I switched to the other that fluid started to come out and never saw a drip from the tranny...

It's a 2000 model, by the way just now I can tell it's haunted XD.

Yeah tell me about it!

When I said fluid was coming out, I meant to say it was actually squirting fluid out of the transmission and not just dripping. After about 15 seconds fluid NEVER came out of the hose. was until I switched to the other that fluid started to come out and never saw a drip from the tranny...

It's a 2000 model, by the way just now I can tell it's haunted XD.

Haunted or possessed? ;) Your 'mechanic' who likes to 'keep' his customers is exactly why I like to do these things myself.

Possesed, thanks!

A year ago I made a promise to myself: "I would never go back to see another mechanic" thanks to the automotive forums and myself...so far, so good.

When I was younger I used to help my father and brother with cars. Then something happened and I wasn't feeling confident on working on cars all by myself. Now I'm back from the dark side and willing to stay like this.

Anyway... I guess I'll just let it be, as far as the transmission works I'm OK with it I might sell "the nightmare" one of these days. Just wanted to comment my experienced and let other users now what they "might" find out.

Regards,

Oscar.

If you had both lines off the tranny, then the fluid would be pumping out of the top line. The idea is to have upper hose attached .... and let the fluid pump out of tranny, though cooler, and then out through the disconnected hose/tube. This helps clean the cooler.

.....or I am very confused. Which is quite likely.

If you had both lines off the tranny, then the fluid would be pumping out of the top line. The idea is to have upper hose attached .... and let the fluid pump out of tranny, though cooler, and then out through the disconnected hose/tube. This helps clean the cooler.

.....or I am very confused. Which is quite likely.

No, you're right. Of course it came out of the top, since the top line is where it pumps from through the cooler, into the return line to the bottom, etc., etc. I'm just a dork.

Oscar, did you put a hose into the hole in the top where the line was? How did you get fluid out?

Oscar, did you put a hose into the hole in the top where the line was? How did you get fluid out?

Negative, I didn´t. I did the exact same process you did, but in my case the hoses had to be interchanged :dunno:

Just to clarify my procedure:

1.-Unplugged BOTTOM line from the transmision and connected the extension hose to the cooler side.
2.- Started engine and expected fluid to come out from cooler side. IT DIDN´T; instead fluid was pumping from the transmission and squirting on the driveway (lucky I had cardboard on it). Turned engine.
3.-Reconnected bottom hose.
4.-Unplugged TOP HOSE FROM THE TRANSMISSION and added the extender hose at the cooler side. DID NOT plug the transmission hole.
5.- Started engine and after a few seconds fluid started to come out FROM the cooler line.

At this point I did the same procedure you posted, left engine on until pump started to cavitate, turned engine off, removed pan, cleaned, replaced filter, put pan back on, refilled tranny with same amount of drained fluid, started engine etc. etc.

Oscar.