Gen4 Prius Transmission Fluid Change

Sorry folks, this is not about Prius. This is about Honda Maintenance Minder.

Yes, A1 and B1 alternate on the Maintenance Minder on our Honda as well. But it is not fixed miles or months for sure. I have always done oil and filter regardless of the A or B service code and tire rotation was always ignored. I do the tire rotations twice a year at the time of winter/summer tire change. For the engine oil change, the car displays % remaining. It starts showing a "Maintenance Required" warning at 15% and goes down, even to minus if ignored.

What I am not sure is how it throws subcode 3, which is transmission fluid change. My son's CRZ was purchased used at ~23K miles 3 years old. I don't know if the CVT fluid had been changed before the purchase. The very first "3" code came on ~22K miles/~2 years later. Then, recently, the Maintenance Minder was showing B1 one day, and a few days later, it changed to B13. It has been only ~14 months 20K miles since the last (and only) CVT fluid change. If the CVT fluid was changed shortly before purchasing the car, then it has to be coming on every 22-23K miles on this car. But, for my HCH which I owned ~7 years/~85Kmiles, I saw the subcode "3" only twice? It is possible that there were more, but my record is showing only twice in 7 years, 85K miles, but I did not DIY the maintenance on this car. It is possible, the code was displayed and I took the car to the dealer and they took care of it but I just forgot to record the details.

 

That's exactly how it works; my GMC is setup the same way. The only component missing is a calendar function; my old Honda and current GMC won't trip the maintenance minder based on annual calendar year - OEM required annual oil change. I've gone more than 18 months without tripping them. My GMC is the fishing/camping truck and I had the Honda when my company gave me a service vehicle. I just changed oil when the tire rotation, popped up.
The maintenance minder programming is based on minimum OEM specification oil, brake fluid, and ATF. So if your putting full synthetic oil into the car, calling for old style dino oil; your not getting any extra mileage out of that maintenance minder. A friend of mine, has a 5 year newer GMC truck. His maintenance minder pops a low as 3000 miles, but he tows his boat and RV into the mountains when we go camping. Those high RPMs and extra heat created probably contributes to those early oil changes.

IMHO: Toyota should've had a similar system on our Primes'; so we're not wasting oil changes - we don't need, when we're running mostly EV mode.

 

Honda has one disclaimer: to change the oil at least once a year, if the maintenance minder hasn't counted down.

 

Just checking in to report that my new to me 2020 Corolla hybrid, which I just picked up with 60,000 miles, is feeling even better after a quick drain and fill of the transaxle. It might have been under filled, because no fluid came out from the fill port when I cracked it open. The fluid looked okay, but was definitely purplish, and somewhat opaque when viewed in a clear cup. It took almost exactly 3.25 quarts to fill. Not making a whirring noise when first going upon cold morning starts. Definitely feels smoother when “downshifting” from higher rpm’s. Sweet!

 

I know that the car should be level when draining and filling the transmission fluid, but I only have one set of Rhino ramps.

Dumb question but is there any harm in draining and filling when using only ramps on the front of the car? I have a 2021 PP. The car obviously won't be level, but I'm thinking that I'd just measure what came out, then fill up the transmission with the same amount of Toyota WS fluid.

Any input would be appreciated. Thanks in advance!

 

The proper fill level is achieved by by adding fluid until it starts coming back out. Toyota doesn’t actually say anything in the repair manual regarding a need for the car to be level, but I’d presume they envisage the car being on a lift for this (level). If the car is on a tilt when you fill, if the fill hole is towards the rear of the transaxle (for example), the fluid will start spilling back out sooner.

do you have a floor jack? Run the front up on ramps and then jack up the rear? Or just break down and score a floor jack and four safety stands. Useful to have the full car on safety stands for brake jobs, wheel swaps and so on.

 

That should be fine; but I would probably add an extra 1/2 to one cup more. IMHO a slight overfill is better than a short fill. This would compensate for residual spillage and left-over oil in your pan. It's a built-in margin of safety.

 

Thanks all for the input. I’ll measure what comes out and goes back in for now. If for some reason the amount of ATF that goes in is less than comes out (because of the car not being level or what not), then my worst case scenario is that I borrow a neighbor’s floor jack and pick up 4 jack stands to finish the job.

My PP is just about to hit 60K miles so I’ll plan to do my first ATF change this weekend.

Thanks again!

 

Did you mean twice per change, like drain and fill, shift gears while idling, then drain and fill again?

Sure, if you are getting a paid professional to do the job: twice the fluid, twice the hours!

It's like boosting shampoo sales: Wash, rinse, repeat...

 

LoL; but good question. The drain and fill x2 is an old recommendation for torque converter automatic transmissions. On an old torque converter transmission, half the ATF is still in the torque converter after a drain & fill. A drain & fill x2 would mathematically get 75% of the old ATF out. Very few of those old transmissions had a drain plug on the torque converter. I think a certain Ford and a certain Chrysler product had this; and after a few years - both stopped putting drain plugs in all together.

When you drain a Prius CVT; 98% of the ATF comes out. The other 2% is in the ATF cooling loop and residual fluid in the nooks and crannies. So IMHO; your wasting money by doing a drain & fill x2 on a Prius.

Hope this clarify things.....

 

I’d do multiple drain and fill only if you’ve got contam, say someone accidentally put motor oil in.

 

Drained mine at 61K, the fluid is still good, the color is red, a little darker. I will wait at least another 80K for the next change.
It's impossible to put back exact amount fluid back with flow out from the fill hole, fluid left in pump, and some leaking from pump. I ended with 3 qt and 12 oz, hope it's ok. And only will know put in how much at next drain.
My pump is something like this,

 

After changing ATF, feel like the car is quieter on highway.

 

Was my plan for years and then COVID and the supply chain issues. Toyota lots are still very limited on selections and the new Prime may be too low to the ground for me and I do not like the battery being outside the interior compartment.
Wound up buying the extended warranty which was not my plan.
Looking for reliable alternatives with great MPG and do not see any yet!
Sat in the new bZ4X and was not impressed with how high it was off the floor, bumped my head climbing in, and could not see the speedometer.

 

LOL. Your comment was quoting my Salamander_King, Oct 10, 2021 comment. Yeah, at that time I had planned to sell the car quickly. I did end up trading in my 21 PP for a huge profit and got a 22 Ford Escape PHEV for a trade (No additional money). Now, I am stuck with the low-reliability FORD for two more years. I'm hoping Toyota will bring the EV (PHEV) manufacturing to the US by 2025, so I can trade in the 22 Escape PHEV again without paying too much for a new PHEV with tax credit.

 

90430-18008 crush washer! Is this part number for all Prius years including Prime?

 

Checked my receipt (for gen 3); it matches.

Still, consider giving dealership parts department a call; that’s their bread an’ butter.

 

I'm doing my 2nd change at about 90K. IIRC its NOT 'lifetime' but every 60K. Old ATF looked pretty dirty. I'm gonna plan on another change at 30K, now that I've got a set of 4X23" tall 6-ton jackstands on order.

Problem I'm having, besides those cursed clips plastic thingys, and the mouse attack, is the little pump that I remember worked fine about 1.5yrs ago, is now barely pumping and only pumps out about 1/2 the bottle after LOTS of under the car stroking, so having to make full bottles out of 1/2 full bottles, AFT dripping everywhere. Off to store or maybe will attempt top pour. At least the old pump has a hose end which sorta stays in the fill hole. Part of problem with old pump seems to be hose got crimps but even squeezing those open with pliers it still seems to have issues pumping.

 

Just go down to home depot and get two or two and a half feet of nylon hose and a funnel. Top fill goes quickly, as long as you don't accidentally tug that hose and pull it out of the fill hole. Go slow on the last quart, it'll be spilling out around the quarter to half quart mark.

Hope this helps...

 

Got a funnel and might try.
Gear Oil and Fluid Pump
Got another one of these that has clip end that does an weak job of keeping it in the hole. Turns out at least part of the problem was I lost the little extension and thats why I was only pumping 1/2 bottles.