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I changed the tranny fluid last week, and made a few discoveries
and observations along the way. All for lack of a long enough
funnel, in a way, but with other benefits. This is starting
to become sort of a maintenance mini-series, although it hasn't
gotten into messing with the other fluids yet.
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_ http://techno-fandom.org/~hobbit/cars/maint50k/
[same as spammed to P_T_S in case you've already seen it]
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_H*

Hi Hobbit:

___Do you have access to the tech manual as I have a hard time believing a tech would remove the cowling and inverter to get at an obscure third fill port. I bet they have nifty little coupling and pump ATF WS directly into the FILL port itself. For a pro with the fill port up front and center while up on the rack, I do not see doing it any other way? I would route some ¼” poly from the top and pour ATF WS directly into fill port via the tubing. Run the ATF in to a slight overfill with the excess draining out and you’re done at 0 mm.

___My $0.02 anyway?

___Very interesting as to the color? I would have thought it would be far more pink then dark red at 50K miles. HSD uses only a few ounces of ATF in total, right?

___Good Luck

___Wayne

Hi Hobbit:

___I may as well ask here … I have access to an 02 Prius that I might attempt to pick up this weekend. She only has ~ 30K miles on her IIRC and you have me thinking … I may as well go for the gusto with a tranny fluid change. Does the manual request a flush or a simple change? Given the simplicity of HSD, Toyota requires a simple swap, not a 3X flush, correct? I thought I had read a year or two ago in the PTS forum that the newer Toyota ATF brought the Prius I’s capability up smartly afterwards? Again, I am very foggy as to the details but you or Mr. Wilson could help with my lack of knowledge hopefully.

___I will read the owners manual when I get my hands on it but by chance do you know of an online manual I can take a peek at? Do Prius’ have a tranny fluid dipstick or any such thing so as to do a visual on the fluid itself without having to go after the fill port and vampire pump a small sample out? I had better start collecting my home made tools by Friday if I am to perform this fluid swap in somebody’s driveway ;)

___Good Luck and thanks in advance?

___Wayne

The manual says to fill through that front hole. Which is
also the only way to check level -- no dipstick. With a transfer
pump or a much longer tube on the funnel, I could have done it
that way but I wanted to see the other benefits of moving the
inverter around.
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I think Doug Schaefer was the guy who actually put ATF-WS into
his Classic, saw an MPG benefit, and so far I haven't heard of
any ill effects yet. The internal parts of either Prius are
very similar in makeup, so fluid specified as part of a design
improvement [NHW20] seems entirely appropriate for the older
transaxle too. I'm sure if Doug experienced something screwy
as a result of his upgrade, we'd hear about it!
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The NHW20 took 3.3 quarts or so for a drain-n-fill. I didn't
consider the whole "flush" thing -- for that, it's just a waste.
The Classic actually takes more fluid, because it's got a bigger
sump pan on the bottom. I think dry spec is 4.9 qt.
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_H*

Wayne

For the Classic Prius it's best to drop the pan, clean the pan, pan magnet and what ever can be reached in the transaxle. Then refill using the front inspection port in Hobbit's guide. Toyota WS does seem like a good substitute for the Type-VI required. There is no way or need to flush these transaxles, unless you have access to some equipment that can spray some fluid under pressure into the sump hole when you have the pan off! Important thing is to loosen the fill/inspection plug first to make sure you can fill it. It doesn't matter the color of the fluid, the classic is pretty rough on Type-VI fluid, so change it.

If you need any more info I have access to the manuals as well, let me know what you need.

Wayne

Hobbit,

As usual great write up. I would suggest, as Wayne kind of alludes to, also having an optional procedure shown for fill from the inspection plug. I just can see some shade tree mechanic who is not that familiar with the Prius somehow messing up a very expensive inverter at some point in disassembly/assembly. Even with your disclaimers I can see it happening.

Wayne

I have access to an 02 Prius that I might attempt to pick up this weekend. She only has ~ 30K miles on her IIRC and you have me thinking … I may as well go for the gusto with a tranny fluid change.

Whatcha mean, "pick up?" Are we talking article fodder or are you going 2G on us? It'll be interesting to hear how it does when you throw the book at it vs. your Accord. The drivetrain is so different I can't even begin to predict what you would do with it.

Okay, I updated the wording in one of the earlier paragraphs
to point out that this isn't necessarily what to do if ALL you
want to do is change the fluid [and have the appropriate
equipment].
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_H*

Hi Wayne:

___Yes, I had better ask for a little guidance given this will be performed on the fly in a driveway … Mainly for torque values and bolt sizes so I don’t have to take up 400 #’s of miscellaneous tools ;) I am sure I will need a new pan gasket and a specific gasket sealant Toyota recommends in the manual as well?

___Can I stop by and pick it up from you if the Prius-I version you have is not electronic? I E-Mailed Cheryl and will hopefully be able to drive hers back by the weekend? And thanks in advance!

___Tim, I am very interested in a Prius I’s highway capabilities (52/45 city/highway) but have some of my own places to string her out. I am very fortunate I do not have to deal with but 30 miles of 65 mph Interstate and 15 of that can be bypassed with Carl’s Warm-up P&G route. Not fully un-molested but un-molested enough to possibly see some decent numbers from the 1st Gen (second actually of course). I am guessing she will allow a touch better then the Accord with a 60 - 65 mpg average over an entire tank but I am not going to throw it away by any stretch! The trip back from Madison will be for SG-II calibration and then the Gloves really come off … When aren't the gloves off is what I should have said ;) It will go in the Review section once complete. The Corolla review/write-up from this past winter was performed in temps far to cold to do it justice given the 49.x tank wasn’t up to any of our standards imho :(

___Hobbit, thank you for updating your guide.

___Good Luck

___Wayne

Another update -- the question came up in multiple places of
how exactly the rear brake self-adjusters work. Nobody had the
answer at hand, so I went out and got it.
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_ http://techno-fandom.org/~hobbit/cars/brkjob/adj.html
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_H*

[QUOTE=xcel;28643]Hi Wayne:


___Tim, I am very interested in a Prius I’s highway capabilities (52/45 city/highway) but have some of my own places to string her out. I am very fortunate I do not have to deal with but 30 miles of 65 mph Interstate and 15 of that can be bypassed with Carl’s Warm-up P&G route. Not fully un-molested but un-molested enough to possibly see some decent numbers from the 1st Gen (second actually of course). I am guessing she will allow a touch better then the Accord with a 60 - 65 mpg average over an entire tank but I am not going to throw it away by any stretch! The trip back from Madison will be for SG-II calibration and then the Gloves really come off … When aren't the gloves off is what I should have said ;) It will go in the Review section once complete. The Corolla review/write-up from this past winter was performed in temps far to cold to do it justice given the 49.x tank wasn’t up to any of our standards imho :(

Look forward to this. I have not been able to do much highway testing in Japan as the highways are not Freeways, costs about 30dollars/70m. Not having trip mpg for NHW10 it is difficult to say but for 120km highway but pulsing between 50mph and 40mph, I was able to see about 70mpg but was heavily loaded with passengers and luggage.

Good Luck
Andrew

Hi from Doug Schaefer. Yes tochatihu the 2001 Prius has had type WS transmission fluid for about the last 23k miles. In fact, now with 0W20 oil and SLLC coolants, it only needs DOT 4 brake fluid to be completely 'wrong' on fluids. That and maybe a tank of premium fuel. :Banane38:

No unusual operation noticed, and yes it may contribute 5 to 10% to fuel economy. But I would rather wait for reports from others on that because my driving since has been very inconsistent in terms of weight carried and power loading of the vehicle.

At some point I will sample this fluid, but the chemical results may not have general significance. This is because I also have a trans fluid filter built by Mike Beyer in Olympia WA. Just last month I took my first look at that filter and no sparklies are visible in it.

The first trans fluid change (still using T-IV) was done at about 78k, but this was before interest arose in fluid analyses. At least I had them wipe out the pan and it was clean. Second change was to WS (as described above) and the old fluid analysis is part of Bob Wilson's data set.

That the classic Prius trans has bushings instead of caged bearings seems to be our only hint that the thinner WS might not be a good idea. But as I say, bits of bushings have not accumulated in my (see-through) filter. That's all I can tell ya so far.

Bob W suggests that there may be up to a kilowatt of 'thrashing' going on in the trans, and we guess that is how the less viscous fluid may improve mpg.

Did somebody say just a few ounces of trans fluid? More like a gallon.

DAS

Hi Andrew and Doug:

___Thank you both for the replies and I am still looking forward to pushing one as far as she would allow. The Prius I review will have to wait however because I do not have the Prius-I in my possession as planned :( I drove up to Madison last night and we had other issues in terms of a completely dead 12V and then code(s) thrown after a 9 second start ritual before she would automatically shut down. An indeterminate code (P0000) locked her out of our control after said 9 seconds and that was that :( I will describe the whole event in another thread about “Community” here at CleanMPG.

___Doug, I was so hoping I had your Cel last night to give you a call. I spoke with Bradlee Fons who had Wayne Mitchell’s number and access to the Internet. Cheryl did not so it was either talk it through by phone or head over to the local library. I had planned a change to WS, Mobil1 0W-20, a new air filter and of course 60 #’s in her RE92’s but that will now have to wait :(

___Bradlee and Wayne, a personal and huge thank you for being there while trying to get the poor girl up and running under her own power … That was an interesting 3-way conference call if I do say so myself ;) With access to the Toyota Techline, I do not think we could have done any better without being in a Toyota shop with their proprietary code readers … Either way, there is a semi-dead 02 that will be picked up by the local Toyota dealership possibly Monday for a Toyota diagnostic and who knows what afterwards?

___Good Luck

___Wayne