Toyota Prius 2010-2015 Transmission drain and refill

That's an issue with other fluids as well. Some overthinking DIY'r might have put the latest-and-greatest (and incompatible) brake fluid in, for example. Same thing for coolant.

This is something you do once in a very long while, don't get clever, keep the fluids "stock".

 

There's two kinds of maintenance, preventative and repair. Shooter up.

 

Think what you may. It was not particularly discolored -- typical few year old looking fluid.

Trans fluid is highly detergent in its action -- not necessarily because of additives ... having it darken a bit is normal and will happen very quickly.

 

...and "typical few year old looking fluid" gets changed regularly...even WS in the other Toyota vehicles. Do what you may.

 

For me it boils down to this, there have been a very small percentage of transaxle failures given the amount of miles the Prius line has been on the road. A very high percentage have never had the fluid changed. Add those up and I have absolutely no concerns about the transaxle in either of my plug-ins. I will change the fluid when I get around to it just because it's fairly cheap, it can't hurt and I can do it myself. However, even if I didn't change the fluid I wouldn't worry about it for a second especially after seeing the 180k fluid that came out of my 04 Prius. The fluid has proven over time to do what Toyota claims.

 

I don't understand the post?

Maybe you are saying that other cars require a change? The service that Toyota and Lexus perform on those cars that call for the service -- is a simple drain. It is a partial refresh -- and they don't drop the pan or change the filter. Most transmission filters are nothing more then a screen -- it's not a filter ... like an oil filter. It would however remove a rouge particle that could be sitting in the pan.

Some cars hold 10 quarts -- some four. The vast majority of cars on the road have no transmission service interval -- and the transmissions outlast the vehicles .. that includes the Prius. If one reads internal fleet management reports you will find that the majority of failures (in all transmissions) are from: 1: leaks that cause low fluid ... and 2: using the incorrect fluid while performing maintenance or fixing condition #1.

Changing it correctly is obviously not going to hurt anything .. although some german transmissions do have built-in software that anticipates changing oil conditions as the boxes age .. this has actually caused some issue in the older early MB and ZF units.

 

Your car, your call. My vehicles, my call. But then again...what do I know.

 

I just did mine today with car on 4 jack stands, the under panel removed, at the same time I did the oil change also! The ATF-WS drained out with dark red color and it's look muddy on the drain pan, it's only 2 years and 50k+ miles. I definitely recommend change it at 50k miles.

I refilled it with 3.7 quarts Toyota ATF-WS and no over flow, I filled it with a plastic tube and a funnel from top of the engine bay, once filled I can touch the ATF thru the fill hole, done! The under panel isn't fun to remove...lots of clips and 6 bolts, this is my 2nd change and my Prius now at 128k+ miles since March 2011.

I'd like to keep my Prius for another 3 years at least before i jump on the GEN IV. Total cost of parts about $45 and a few hours, I think it's worth the work just for preventive maintain. I also take advantage while the car on jack stands, I rotate tires also.

 

Good going!

 

(Prepares to mount hobby horse.....)

Ahem, would a reasonable recommendation from that data be to,have a leak-detection device like a transmission dipstick or low fluid warning light installed on each vehicle?

 

that, I would consider overdoing it//

 

Idk about that.. im gonna do mine at 62k i bought the car with 43k miles im not sure if the previous owner changed the fluid, im not taking any chances.. i realize that some prius can go that far without a change , but it would only benefit the car if you do it!! .. i recommend doing it if you want your Prius to run for more years.. in my opinion

 

I'm changing the trans fluid in my 2015 Prius. There appears to be a second drain plug as shown in the top middle of this photo. The primary drain plug has been removed and the hole is visible in the bottom left of the picture.
Should I open up that second plug, or would I just be asking for trouble? Thanks for considering my question.

 

That's the inverter coolant drain, don't touch.

Boy, rust's taking a toll.

 

Thanks.
This is a Maine car. Just bought it. I'll have FluidFilm applied to it unless you or somebody can suggest something better.
I really appreciate your reply today. Now, I'll finish my trans fluid change, using your hints of course.

 

Regarding rust... For all but one of the 10mm bolts (even using penetrant) the heads snapped off. It's going to be tough to reinstall the plastic securely. I may try gluing in some spots with Goop. I have no idea how to get the rusty studs out of the holes.

 

We're on the west coast, relatively temperate climate. But do drop down below freezing, and they salt with a vengeance. Malls too are just nuts about litigation I guess, salt the beejesus out roads/sidewalks. About 3~4 years after new purchase, I was looking at our rear suspension, saw a dismaying amount of rust.

Someone here recommended boiled linseed oil. I gave that a try, worked very well, applied with brushes and rags.

 

The correct drill size and a tap to make new threads. Start with a small bit to get centered then step sizes up to what's needed for the tap.
You could go to a larger size if needed, english or metric.

 

I'll be sure to try that. Thanks.

 

ALWAYS remove the FILLER plug FIRST!!!
Then the drain. If you can't get the filler plug out, you don't want to train the
fluid out because you won't be able to install the new fluid.