Inverter Assembly Maintenance

Yes on the inverter coolant although a little early.

A little early, but OK on the spark plugs too.

If the transaxle oil has not been replaced, have it done too.

GOOD LUCK!
Bob Wilson

 

Have you read the Scheduled maintenance Guide that came with the Prius?

 

If your handy around a car do the plugs and transaxle yourself. Inverter let the dealer do it.

Wayne

 

Keep in mind, the transaxle/drive unit uses WS type ATF. DO NOT USE ANYTHING ELSE!! You will need to remove the drain plug and let the old fluid drain. Then reinstall the plug and remove the fill plug located halfway up the drive unit on the front side. You will need a pump of some sort to get the WS ATF into the unit.

Changing the coolant in the invertor is best left to the dealer since air bubbles in te system can quickly cause over heating and damage.

BIG $$$$!!!

 

For the ATF, it has previously been suggested - wise to confirm you can remove the fill plug before letting the fluid out through the drain hole.

 

Little reminder here.... Toyota does not recommend a service interval for WS ATF. Unless it is contaminated somehow, or work is being done on the drive unit, the fluid should never require changing.

 

Just curious, what having it tested, costs, compared to having it changed. If you've already put 100K on it and intend to put another 100k on, Would it be just as practical to go ahead and have it changed in case there's some metallic particulates from the first 100K of metal on metal wear?:noidea:

 

If you've never had the transaxle fluid changed, I suggest you take a look at this thread:

http://priuschat.com/forums/care-maintenance-troubleshooting/38524-transaxle-oil-analysis-9.html

I changed mine at 20K, and was glad I did.

 

Re: my earlier post #8. I wonder, since there are cases of contaminates as early as 20K, if it would be a good idea to go ahead and the transaxle fliud changed along with the first oil change. This may help eliminate the possibility of any factory contaminates or particles from any extraordinary wear during the break-in period. I don't know the cost so the benefit may not be worth it, but we are planing to keep ours indefinately, and tend to err on the side of longevity. I used to do my first oil change @ 700 miles, to get rid of the break-in contaminates, but that was before the new metals, factory break-ins, and testing.

 

Hi Dave,

If you can DIY, the cost will be ~$20 for 4 qts of ATF WS plus $2 for two new aluminum washers.

dogfriend changed his transaxle fluid at 9,562 miles. Following are the results of his testing:

Fe: 64 ppm
Al: 30 ppm
Si: 147 ppm

Note how high the Si is. Is this due to transaxle case sealant leaching into the fluid or is this dirt? Bob Wilson has been conducting an experiment over the past several months with fresh WS ATF left in close proximity to a layer of sealant, to see what happens.

Here is the Yahoo link to the file folder where dogfriend's test is stored. You may need to be a member of the Yahoo toyota-prius-sat2 group to view the various transaxle oil test files (mostly stored by Bob Wilson). My test at 33K miles can also be found there.
http://autos.groups.yahoo.com/group/toyota-prius-sat2/files/transaxle%20oil%20tests/

 

Thanks Patrick!