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Toyota Prius Transaxle Fluid Changing Details You Need to Know Before Attempting

Here’s how easy it is to change the transaxle fluid on your Prius as long as you are aware of some not-so-minor details to avoid making a mistake.

Doing your own vehicle maintenance is a good way to save money and the best way to avoid a service center scam or maltreatment of your beloved car. However, as the saying goes “The road to hell is paved with good intentions” you have to be sure that you know what you are doing---especially when it comes to DIY car maintenance and repair.

Why? Because as another saying goes, “The devil is in the details.”

Bad Manuals, Missing Information, and Poor Translations

If you are an experienced DIY type, you will unavoidably have learned the hard way that following those step-by-step instructions within a single maintenance or repair manual is not always without problems.

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In fact, it is not uncommon to come across repair manuals that are just plain wrong, lacking key steps, or are manuals originally written in another language that were confusingly translated.

True Story

For example, when I was first learning about rebuilding simple two-barrel carburetors I made the mistake of relying on the instruction sheet that came with the rebuild kit. The instructions were clear, the images good, and being an early model two-barrel carb, it was not exactly rocket surgery. Foolproof. Right?

After reading the instructions thoroughly before disassembly, I began my usual practice of carefully laying each part out in order on a well-lit cleared surface (my apartment kitchen floor) all the while taking photos with one of those “Instamatic” cameras from back in the 80’s so as to avoid any confusion upon reassembly.

In fact, this all worked great. Reassembly went without a hitch and my vehicle started up right away after pumping the gas pedal a few times. It was a success…until it wasn’t.

Turned out after about 15 minutes of driving down the road, my vehicle would die on me as if it had just ran out of gas. I discovered that if I waited a few minutes and pumped the gas pedal it would restart and down the road I would go…for another 15 minutes before the engine died on me. A cycle that repeated itself endlessly.

After taking the carburetor apart and reassembling it twice more, the problem persisted. On my fourth attempt at it I discovered that the bowl float was getting hung up on a small piece of rubber nipple. The rubber nipple was from a small valve I had inserted which involved pulling it through the wall of the carb to secure the rubber valve in place. That rubber nipple it turned out was sticking out just enough to snag the carb float that had the job of adjusting the fuel flow into the carb. Which is why it felt like I was running out of gas…because in this sense I was.

Turning to another reference source I discovered the original kit instruction sheet left out the “Be sure to clip off the valve nipple after installing the valve” detail that had been the bane of my repair.

To quote who I felt like at the moment: “DOH!”

The lesson here is that it is always best (and sometimes necessary) to use multiple reference sources---manuals, repair videos, advice, etc.---whenever tackling a maintenance task or repair the first time.

Toyota Prius Transaxle Fluid Changing Details

To avoid one of those Homer moments with your Prius, here is a very useful explanation and demonstration of how easy it is to change the transaxle fluid---as long as you pay attention to the details provided by the host such as don’t drain from the wrong plug. It happens more often than you would think.

Follow along with the host of the Toyota Maintenance YouTube channel as he works on a 2004 Prius with only 86,000 miles on it and also see why it’s not just the miles, but the age of the Prius that also determines when you should change your transaxle fluid.

Related article: Never Do This to Your Toyota Warns a Toyota Mechanic

How To Change Transmission Fluid on Toyota Prius

For additional articles related to maintaining your Prius, here are a few useful articles for your consideration:

Timothy Boyer is an automotive reporter based in Cincinnati. Experienced with early car restorations, he regularly restores older vehicles with engine modifications for improved performance. Follow Tim on  “Zen and the Art of DIY Car Repair” website, the Zen Mechanic blog and on Twitter at @TimBoyerWrites  and Facebook for daily news and topics related to new and used cars and trucks.

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Image source: Pixabay