Gt4r97

I've been planning to do my own transmission fluid flush(i prefer to do the Amsoil way) but little bit confused about which cooler line should be disconnected, the output cooling (send) line or the return line? I made a search and read a lot about this topic but need final clarification. Thanks in advance!

GSGALLANT

It doesn't really matter. But it's best if you disconnect the return line back to the transmission (after the tranny cooler in the radiator, or if you have an aftermarket cooler, then disconnect the line after that.) That way, you're flushing out as much of the old fluid as possible.

Here is what I did:

1. Remove the tranny pan drain plug, and allow fluid to drain from pan (approx 3-4 quarts should drain out).

Note: Steps 2 to 4 are not necessary, but I highly recommend doing them.

2. Consider removing the pan while it's drained to clean the filter screen and the magnets at the bottom of the pan (this will add an hour or two to the job.) There is still some trapped fluid at the bottom of the pan, so keep your drain bucket and rags handy while you remove the pan. Also, Careful when you remove the filter. More fluid will fall out of it when you loosen the bolts that hold it in. To remove the pan, I had to disconnect the sway bar endlinks, and tip the sway bar down to get enough clearance to fit the pan through. Also, the dipstick tube is in two pieces. Approximately 1 foot of the tube is fixed to the pan. The top part of the tube just slides into the bottom part of the tube (approximately 3/4in) and is sealed with an o-ring. You have to give a bit of a tug to get the two pieces apart.

3. To clean the filter screen, just spray it out with brake cleaner. Let it dry before re-installing it.

4. Clean both gasket surfaces thoroughly. Re-install tranny pan (I use a gasket maker called "the right stuff" made by permatex. It works well, and you don't have to wait a long time for it to cure before you can re-fill your transmission after you put the pan back on.) Use a criss-cross torque sequence pattern to torque the bolts. Be careful not to strip any threads.

5. Re-install tranny pan drain plug, and refill tranny pan (through dipstick tube) with ATF. Put in the same amount that you drained from the pan in steps 1 and 2. Use the dipstick to verify that you have the correct level in the pan.

6. After having drained and refilled the tranny pan , you can then flush the rest of the fluid out by disconnecting the ATF cooling line coming from the stock tranny cooler in the radiator (the return line to the tranny), then, start the truck and let the tranny pump spit out approximately 1 quart of fluid.

7. Shut off the truck, and top up the tranny fluid through the dipstick tube. Repeat this 11-12 times or so (depending on the capacity of your transmission), to flush the majority of your fluid, with very little waste.

8. Reconnect ATF cooling line to tranny cooler.

9. Run truck for a few minutes, then check fluid level. Top up if necessary.

10. Be sure to recheck the fluid level after a longer drive when the fluid is up to normal operating temperature.

Gt4r97

Gsgallant,
Thanks, man! Finally I have gathered enough courage/knowledge to proceed with my long stalled plan - to do my own tranny flush & fill. The dealer nearby charge $150 for complete transmission service drop pan, clean filter, etc. I said, For that amount I can get myself 20 qrts. of Amsoil ATF. Just wish me luck, fellas!

GSGALLANT

Do you know what model tranny you have?

Also, to my above post, I would add that before you even start, check the level indication on your tranny dipstick with the truck not running (normal level check is done with engine running after having slowly cycled through all the gears and back up to "P".) Remember what that level is, because when you refill your tranny pan after taking the pan off to clean the filter and magnets, you want to check to make sure you have enough fluid in there without starting the truck (this is before you flush the rest of the fluid out.) It you start the truck after re-filling the pan and before disconnecting the cooler return line, you will mix old fluid with your new fluid.

Post up if you run into any trouble. I usually check for new posts quite frequently.

Gt4r97

you're suggesting that after cleaning filter, magnet, etc., and refilling the pan ...and also before disconnecting the cooler return line, i have to check fluid level first to make sure there's enough fluid in the pan before starting the truck. Is that what you mean? What's up with the mixing of old and new fluid? Please bear with me, first timer!

GSGALLANT

Yep. That's exactly what I mean. But if you're careful in measuring how much comes out in total when you first drain the pan (including what's left in the bottom of the pan after you remove it and what comes out of the filter when you remove it), and you make sure that you refill it with the same amount after re-installing the pan (before you start the truck at all), then you will be fine. You should pick up a new crush gasket for the drain plug before you start this project, too. There are a number of gaskets on your tranny filter also (make sure they're still on there before re-installing filter)... you can re-use those.

For the mixing of the fluid, I meant that after re-filling the pan with new fluid, if the tranny cooler line is not disconnected when you start the truck for the first time (before flushing the rest of the old fluid out), then the 11 or 12 quarts of fluid that is left in the tranny cooler and lines and the torque converter and valve body (which is old fluid) will re-circulate back into your tranny pan and mix with your new fluid.

So after re-filling your pan with new fluid, your next step is disconnect your tranny cooler return line and put it in a bucket, then have somebody start the truck while you watch 1 quart of fluid (old fluid) come out into the bucket. Get the friend to shut off the truck and add 1 quart of new fluid into the dipstick tube. Repeat this start truck, pump out 1 quart, shut off truck, add 1 quart another 10 or 11 times to get all the old fluid replaced with new fluid.

When that's done, you can reconnect your tranny cooler line and start the truck. With your foot on the brakes, shift through all the gears slowly from Park to Low and back up to Park. Leave the truck running and go check your dipstick (standard procedure for checking auto tranny fluid level). Since your truck has not been running long, your level should be in the cold range. Top up or drain a bit of fluid as required until you're in the range. Once you get that right, then check your level again (hot range this time) after a driving trip that warms up your tranny to normal operating temp. Adjust level as required. Congrats you're done.

Don't worry about asking questions... that's the best way to learn. The other way to learn is to do something wrong, and have to spend lots of money making it right again.

IMPORTANT: If you don't have them already, get the torque values that you need before starting this job (filter bolts and tranny pan bolts). Aluminum threads are surprisingly easy to strip, and the torque on those tranny pan bolts is a lot less than you'd think it has to be. If you don't know those values, post up your transmission model and ask for the torque values. If you're unsure which transmission you have, check the sticker on the truck body (open your driver's door... you'll see the sticker in there.) Look for the codes that look like this: A/TM A04A/A340F. The A04A code is the axle code (A) and the A340F is the transmission code (TM). I think that on your truck, you either have the A340H or the A340F transmission.

Gt4r97

Whew! Thanks for having the patience in educating me, man. My next move is to get all the things I need to do the job esp. a torque wrench if you don't recommend tightening those bolts by feel. I purchased a clicker recently at Harbor freight and it doesn't seem to work.

With regards to my tranny model, I have the A340F. Please let me know what are the torque values for the filter and pan bolts? Thanks!

GSGALLANT

The torque value for the four bolts for the strainer is 84 in-lb. Be aware that there are three different lengths of bolts for the strainer. The two short ones go in the two holes towards the front of the transmission, the medium one goes in the middle hole, and the longest one goes into the furthest hole back.

The torque value for the 19 tranny pan bolts is 65 in-lb. These are both inch pound values... not foot pounds. Small values like this are hard to "feel", so I would recommend buying or borrowing a torque wrench. Decide on the torque sequence you want to use on the pan bolts (I can attach the drawing for the sequence I used if you want when I get home), then use liquid paper or something to write the numbers for the order you'll be tightening the bolts near the bolt holes on the pan itself. It makes it way easier to go through the torque sequence and get it right.

I've also sent you an email.

whitt13

I need to flush my 2001 sequoia 4X4.

This is a good description, but I also read that some toyota transmissions don't send all the fluid to the cooler, so some old fluid gets dumped back into the reservoir. This would mix the old fluid and the new as you flushed useing this method.

Also couldn't I just hook the return line from the cooler to fresh fluid, and let it gravity feed back into the transmission as the transmission pumps the old fluid out?

This would eliminate you from needing to do 1 quart at a time. Would this work?

GSGALLANT

This method will accomplish as good a flush as you will get in most shops. It is doing the exact same thing except without using an expensive tranny flush machine. You are right that a small portion of fluid is recirculated through the valve body and back into the reservoir, but that amount is minimal. Most of the fluid goes through the torque converter and out to the tranny cooler.

The only way to avoid this small amount of recirc, is to do a flush by connecting a fresh supply to the tranny pump inlet (with the pan and filter removed), and collecting the return to the pan (or where the pan would be) in a drain pan. I have never found a shop that does it like this, but I'm sure you can find one if you look hard enough. I wouldn't recommend a DIY on this method.

It would be really difficult to control the inflow to match the outflow in the method that you are thinking about by connecting a fresh fluid bucket to the return line. Keep in mind that there is no suction on that return line. Fluid flows through by being pushed through the send line to the cooler. You can, however, have somebody pour ATF down the dipstick tube continuously to try to match what is coming out as the truck is running, but if he falls behind, shut the truck off to avoid running the tranny dry.

In my opinion, the price of a new tranny is enough that I want to ensure there is always fluid in there, so I want to avoid scrambling to try to keep up to the tranny pump. The way I described above is easy and controlled and it is really hard to screw up while you're doing it if you take your time (which is perfect for most DIY projects).

GSGALLANT

Here is a link to the picture showing the torque sequence that I used on the tranny pan bolts.

I torqued the bolts in two passes. First pass at 40 in-lb and the second final pass at 65 in-lb.

rearviewmirror

Good thread!

Lazybummm

allow me to spawn this thread...kick ass thread, will look at this in a bit. Which is the best way to determine which one is the in and which one is the out on the radiator for the cooler lines? I have a 97 3.4 4runner, because I've read that some are on the passenger side, some are on the driver's side. TIA!

rxcrider

As for figuring out which one is the return, the one farthest from the torque converter is a good guess. I picked that one, unhooked it and attached hoses to the line and the fitting on the transmission. After that, I started the truck and watched to see which hose the fluid cam out of. My guess was correct. On mt '01, both cooler lines are on the pasenger side with the rear line being the return.

I did my flush as part of a trasmission swap. The fluid had been drained from the converter to whatever extent is possible by setting the converter on end and that the pan had been drained before I got the tranny and I really didn't want to run dry so I overfilled it before starting the engine. I discovered that you can't overfill it too terribly much. It runs out the return fitting on the transmission. If I had been really smart at the time (3 AM and the Mountain Dew was only keeping half the brain cells functioning), I would have checked the fluid level and then counted the quarts from full to leaking out the return so I could adjust things nicely at the end. As it was, I sort of winged it and after I had flushed through enough fluid to have new looking fluid coming back out, I had to start it a few more times to pump the level down a bit. At the end, I came pretty close and only had to add a 1/2 quart after my test drive.

I guess the only real points to that long winded babble are that a quick experiment can tell you which one is the return and that you can add extra oil 'til it leaks out the return fitting to help prevent running dry.

ARB1977

I bought two cases of Redline D4 when i did mine at the time. I didnt drop the pan i just disconnected the return line from the tranny and had my buddy start up the truck till a gallon came out, then refilled the pan with 4 qrts, repeat process till the fluid is clear red. Now every 30K i drain whats in the pan and refill. Everytime ive done this the fluid comes out clear red. To make filter changes eaiser i installed a remote filter kit between the factory cooler and trd cooler with a filter magnet from filtermag.com.