Changing 10R80 Fluid cold? Is it possible?

[Dave1965]

I realize that to properly (according to the FSM) change the transmission fluid, its done hot and level checked with the engine running.
My thing is, that I don't want to get burned by the exhaust system adjacent to the transmission dipstick/fill plug.
Is it possible to pump out old fluid on a non-running vehicle and pump in the exact amount of new fluid?
I know on some vehicles I've had, if you opened the fill plug with the engine off, fluid would spill out due to more being in the pan and not circulating via the pump. T
This is obviously a "better than nothing" solution but I was just wondering if it is possible?
Vehicle is a 2025 XL Supercab 4WD with the 3.5

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[Mosey]

Yes it is. I just did it on my 2021. Seven qts out and seven in. Easy pesy….

Rather than pumping the new fluid in I rigged up a funnel and 4 ft of tubing and did it from the engine bay.

 

[Davexxxx]

Yes it is. I just did it on my 2021. Seven qts out and seven in. Easy pesy….

Rather than pumping the new fluid in I rigged up a funnel and 4 ft of tubing and did it from the engine bay.

Did you do a write up of that. I'd be happy to read it.

Did you note the level on the dipstick?

 

[Mosey]

I did not, but I can if you like. I cant get to that until later.

 

[Davexxxx]

I did not, but I can if you like. I cant get to that until later.

At your convenience, thanks!

 

[Dave1965]

Yes it is. I just did it on my 2021. Seven qts out and seven in. Easy pesy….

Rather than pumping the new fluid in I rigged up a funnel and 4 ft of tubing and did it from the engine bay.

What was your mileage and the condition of the old fluid?
Has shift quality improved?

 

[FirstFord]

I realize that to properly (according to the FSM) change the transmission fluid, its done hot and level checked with the engine running.
My thing is, that I don't want to get burned by the exhaust system adjacent to the transmission dipstick/fill plug.
Is it possible to pump out old fluid on a non-running vehicle and pump in the exact amount of new fluid?
I know on some vehicles I've had, if you opened the fill plug with the engine off, fluid would spill out due to more being in the pan and not circulating via the pump. T
This is obviously a "better than nothing" solution but I was just wondering if it is possible?
Vehicle is a 2025 XL Supercab 4WD with the 3.5

Possible? Yes.
Advisable? That is somewhat debatable....

Removing fluid, measuring the amount withdrawn and replacing the exact same quantity with new fluid, sounds perfectly logical - and it is. Except it is based on the assumption that your transmission currently is filled to the correct level, which it may, or may not be. There are a number of threads on this forum reporting how their transmissions were under-filled from the factory, and a few that were over-filled. If your transmission was one of those, then your quantity of measured removed fluid will be based on an error fill. All in all, the chances of your transmission level having the correct fill level from the factory is good, but it is still something to consider, especially for the first fluid exchange. Once you establish a known correct baseline to start with, then the logic of replacing the exact same amount removed with new seems much more reasonable.

As for me, I'm a little old fashioned, and maybe a bit of a "scaredy-cat". I paid more for my truck than what I paid for my first house, and I don't want to do something that will mess it up. So, I prefer to do things the way Ford wants you to - checking the fluid level when it and the transmission are hot. Your fear of getting burned during this process is rightly justified. However, there are inexpensive forearm/glove burn protection garments available. Using something like this will protect you:

https://www.amazon.com/Mechanix-Wear-Resistant-Kevlar-Sleeves/dp/B000R7LZH8

(There are a number of different styles, manufacturers, and prices out there. Shop around.)

 

[Mosey]

Here is a quick writeup on my procedure to do a cold extraction and replacement of transmission fluid in my 10R80MHT.

First off I need to discuss the one assumption I made. At 29k miles I had my transmission pan replaced due to a crack. Since the pan was off I paid to have a new filter installed. My assumption is that the dealer did the job correctly, and since there are no signs of leaks and the transmission has operated correctly, the fluid level was correct.

The night before I put the front up on ramps. I let it sit about 14 hours. I don’t know if any additional fluid would drain down, but I gave it some time to do so. The next day I removed my skid plates and got everything ready.

I blew off the area around the filler/dipstick hole to be sure I would not drop any contaminates into the hole. Using a 19mm crows foot I broke the dipstick cap loose and removed it and the dipstick. The fluid level was at the top of the dipstick. Normally you check the transmission with the engine running so I was not surprised by the level.

Next I inserted the extraction tube into the fill hole and began the extraction. The tube is 1/4 inch ID (Not shown here).

It took about 20 minutes to extract all the fluid from the pan as I had to empty the reservoir twice. I also climbed under the truck and repositioned the tube a few times to get out as much as possible.

I was able to remove almost exactly seven qts as shown in this photo.

The old fluid was a dark brownish red, not very appealing. It is translucent but the photo does not show that.

The last step was the refill. I took a small funnel and attached a four foot tube to it. The tube must be small enough to go into the dipstick hole.

I fed the tube down from the engine compartment and into the transmission. Tip - warm the bottles of tranny fluid to room temp so it flows faster.
.

I put seven qts of Motorcraft ULV back in.

Lastly I reinstalled the dipstick and cap, tightening the cap snug but no more. From the factory the cap is installed very tight.

 

[FaaWrenchBndr]

Yes it is. I just did it on my 2021. Seven qts out and seven in. Easy pesy….

Rather than pumping the new fluid in I rigged up a funnel and 4 ft of tubing and did it from the engine bay.

that’s how I have always filled Toyota transmissions, Tacoma & FJ

 

[Trainmaster]

If I'm dropping the filter to change the screen, I drain them using a $6 plastic mason's mixing box (the tub for mixing concrete) from Home Depot. It's big enough to catch the drips and spills along any cross member or pipe. Then I pour the contents of the box into containers to measure what came out.

If I'm not dropping the pan, I use the same OEM Tools pump that Mosey shows above. It works great and is pretty inexpensive.

Never thought of the funnel idea. Thanks, Mosey!

 

[FaaWrenchBndr]

If I'm dropping the filter to change the screen, I drain them using a $6 plastic mason's mixing box (the tub for mixing concrete) from Home Depot. It's big enough to catch the drips and spills along any cross member or pipe. Then I pour the contents of the box into containers to measure what came out.

If I'm not dropping the pan, I use the same OEM Tools pump that Mosey shows above. It works great and is pretty inexpensive.

Never thought of the funnel idea. Thanks, Mosey!

I agree that pump is a great unit

 

[Trainmaster]

@Mosey, does it take two hours to get the fluid from the funnel through that 4-foot tiny hose when the fluid's at room temperature?

 

[JohnTrigger]

Thanks for the nice write up Mosey

 

[ApolloChurchill]

I evacuated the fluid cold from my truck when I did the PPE pan upgrade. My truck had sat for two weeks at the time and I got 9 quarts out of it. I was also adding the factory auxiliary transmission cooler so I figured I’d be a little short but when I put 9 quarts back in I was severely short, it wasn’t even on the dipstick and was making cavitation sounds when trying to get the trans to temp. In the end it took 11 quarts total to get to full during a proper hot temperature check of the dipstick.

 

[Mosey]

No, only about 5 minutes per quart at about 50 F. A larger tube may fit, I just used the one I had.

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