Transmission flush

Just responding to WS=WS

 

I saw a procedure from a toyota manual at some point that had instructions for a full ATF change without removing pan. Steps were drain pan, refill, start & run ? seconds, turn off, repeat 3 or 4 times.

I forget how long to run but it wasn't long. Just enough to push a little fluid around but not really mix it much. I think it was on this site when i found it last year..

 

I agree but I think next time I will get the aisin ws fluid. It is identical as far as I can tell and even cross references to the toyota part number for ws

https://www.rockauto.com/en/moreinfo.php?pk=7668692&cc=3437071&pt=11387&jsn=870

If you scroll to the bottom u can see the references I am talking about

 

Do you have a link to any explanation or videos of how to do that process? I have an '18 with the factory cooler, and would love to just refresh all the fluid in one go, if it's really that easy

 

This one is good, not exactly the method I described, complete exchange and thorough. Drains fluid from the transmission cooler line in front of the radiator and refills from the fill plug on the trans using a large funnel and hose from above.

https://youtu.be/cB8MdGgwg68?si=Ixak017Zh6fPJD56

 

Awesome, thank you sir!

 

Unless you can find a different license number for Toyota WS (Toyota World Standard), I think you are mistaken. The Amsoil Signature Series fuel-efficient fluid that meets Toyota's WS specs has this license number listed... JWS 3324, one of only 2 Toyota listed numbers I can find.

 

This is the fluid that I bought, and from Rock Auto as well. I'll confirm that it has been working perfectly for about 10k miles on a full fluid exchange and I have not been easy on it. Lot of towing and long trips. I've never seen over 210 degree pan temps even with heavy loads and the trans shifts nice and smoothly.

This process works great. I referenced this same video earlier in the thread as well. This is the exact procedure I followed and I had no issues with it. I used a total of 14 quarts in the process (I'm glad I bought extra!) I removed 3 quarts at a time, then refilled the pan. I stopped once clean fluid came out of the hose. Obviously I lost a little bit of the new fluid in the process, but that was expected and why I had extra on hand. I may do drain and fills from here on out, but it was nice to get a fresh start given that I bought the truck used.

 

Didn't realize that was the same one you posted!! Great minds and all I guess...

 

Torque converter goes through everything in sump in seconds. Within a minute, way under minute in fact, old and new fluids are thoroughly mixed. The only place where a few oz of old fluid can remain is accumulators, valve body passages and plungers that have not been activated yet.

 

This is a messy version of drain and fill, and offers no benefits.

 

Please explain the messy and no benefit part. I believe this method allows for a better exchange old and new fluid. It is essentially getting the pan almost empty, and then you are filling the pan with fresh. It is done in steps to mostly empty the pan and then put fresh in to chase through the trans pushing the old fluid out in the process. Drain and fills of course give you the 3-4 qts of fresh to mix in with the remaining 8 qts or so in the trans. I understand there is benefit to doing the drain and fills, but this method seems to exchange a higher percentage of old for new.

 

Oil pump picks fluid up from sump at flow rate higher than ever needed. The excess pressure is cut off by linear pressure solenoid and drained back to sump. Line flow then circulates in valve body, et al. Its pressure (linear pressure) is way higher than any cooler can take safely, so the cooler line excess pressure is cut off by spring-loaded cooler bypass valve. Only a small fraction of ATF fluid is diverted to the cooler, the rest goes back to sump. The colder ATF is, the lesser amount gets to the cooler.

 

Thought the bypass was pinned open during this procedure?

 

No, that is not the bypass valve you have in thermostat. It is in valve body. Most of anything going out of valve body is governed by one or another kind of valve.

 

Good explanation @vtl , but even if this is just a fancy drain and fill, it does work quite well as a fairly comprehensive fluid exchange. Even if some old fluid is leftover within the transmission, it was quite obvious to me once the process was mostly complete as I could clearly see a change in color of the fluid during my last drain.

 

It does not do any better (nor worse) than drain & fill. Just don't wait till ATF starts to bubble before refilling what you've got out, it causes damage to the transmission.

I do post-winter inspection for my vehicles: getting them on ramps, dropping all the skids, washing off dirt/salt, repairing rust, etc. At the same time I do drain&fill, which refreshes about half of fluid in Tundra and Sequoia and about 1/3 in my other car. Doing it through the cooler line is pain in butt for me. Especially with gen2.5 Tundra, I fear I break grille plastic tabs every time I need to get to the radiators.

 

Yup I made sure to only do 3 quarts at a time for that reason, well before I sucked the pan dry to avoid any damage. Since I had bought the truck used it felt nice to start fresh, but as I stated earlier I'll likely just to regular drain and fills from now on as required.

And yes I understand the hassle of basically pulling apart the entire front end! It is certainly less than ideal.

 

I found the Toyota service sheet I was thinking of. Header of the sheet says it's for the A760E transmission in 2015 Tundra shop manual. Seems like you could do same procedure for other transmissions and I assume main difference should be which temperature range you get the pan to before pulling the check plug.

It instructs to drain, fill, start truck, move shifter from P to S and S1 to S5 then back to P, then idle for 30 seconds and turn off. Then go do it all again. Then again. After the third fill is when you let pan get up to the temperature range and check the overflow for a trickle.

You transmission number should be on the door sticker with VIN and all the other info.
There was another thread where someone with TIS 2015 shop manual said this:

AB60F pg3276 99F to 111F
A760F pg2933 127F to 138F
A760E pg2933 127F to 138F
AB60E* pg2816 99F to 111F

 

So if I decide to just do a drain and fill should I pin the thermostat for the cooler open? Or just drain the pan, about 3 quarts and put back in the pan the same volume that came out? Then do the proper quantity at the end when the trans is at temp?

My plan now, unless someone tells me different:
1) drain the pan
2) put back in the same volume of ATF that came out (Amsoil though)
3) start truck and cycle through gears for 2-3 min
4) repeat step 2 and 3 maybe 4 times depending on colour of atf being drained
5) once satisfied that most of the fluid has been replaced, albeit mixed and replaced do the proper steps to ensure the correct level of ATF is in the pan.

I read that the pan should be between 108*F and 118*F. I saw a video where the guy was checking his atf temp with a temp gun on the pan - I’ll likely do that as it seems easiest.

 

Pointing an IR at pan is not great for actual fluid temp. If you have a Scangage or something that reads ATF temp via port under dash that would be best and check door sticker for which model trans you have to know what the correct temperature is.

 

Unless you have added a cooler a 2021 will not have a thermostat to pin. The correct temp is 99-111 and you check it with the engine running. You should definitely use an OBD tool and not a thermometer to check the temp.

 

Pardon my ignorance, but why does the trans need to be a certain temp? Let’s say ambient air temp is 70 degrees and engine is cold. Why stops someone from draining the pan and simply putting in exactly what came out? Not speaking towards an entire system fluid change, just a simple one time drain and fill.

 

technically if ur confident in the amount in trans ur not wrong

 

I have done what you are talking about when I thought the check process was too complicated but once you learn how easy the check process is, it makes a lot more sense to do it the right way than mess around measuring what comes out to put back in. The reason the fluid needs to be a certain temp when you do the check procedure is because the fluid expands as it gets hotter so if you check it to cold not enough will come out and if you check it too hot too much will come out.

 

In the case for the temperature, wouldn’t you need to have both the transmission fluid temp and the temp of the new fluid the same? If trans temp is 106 and you add room temp fluid, say, 70 degrees until it trickles out, then once that added fluid heats up, it’s going to expand and technically be overfilled? I’ve also worked all day today and chased a 19 month old all evening so my brain is a little fried

 

@Jaypown so you should only do the drain and fill with the truck fully cold. Then only after draining and filling, would you start the truck, let it warm up to 99-111°F, and then check. So you wouldn't cold and warm fluids

 

Could someone clarify something for me. When pulling the plug to check the level, is the engine still running?

 

Following now.

But @parkerbows, if you’re confident in the fluid level before you start, the replacing what came out would still be just as effective.

 

As someone already stated, you do a drain and fill cold then add about 4qts and do the check procedure when it warms up.

Yes engine must be running to do the check.

Only way you can be positive though is if you have done the check procedure before since even from factory the trucks have been over filled, mostly 19+ since it seems the factory filled them with what they would have had if it had a cooler on it. Once you have done the check procedure though, you would just do it again the next time since its actually easier than measuring the fluid. You watch the temp on your phone from an obd app and then open the check plug at the correct temp, its not a complicated procedure.