Subaru cvt fluid change

[ammolab]

Temperature is needed - between 95-110F if I recall correctly, because fluid mass expands and contracts based on temperature and you want to fill to the correct level at the correct temperature to avoid issues.

So drain at ambient temp (car sitting over night) and fill with same volume of fluid sitting next to car overnight. Same temperature = same expansion.

 

[stwremains]

So drain at ambient temp (car sitting over night) and fill with same volume of fluid sitting next to car overnight. Same temperature = same expansion.

I can see how that should work, Im just sharing what the service manual states!

 

[aba4430]

If there were no issues with the transmission prior to drain, then drain and fill with the same volume will be acceptable. However, if the tranny was underfilled at the factory you would not know. Example: I did a drain and fill on our 17 OB with the 580 tranny last December. I drained ~4.75 quarts of CVT fluid and filled with ~5.4 quarts of CVT while the temperature was ~95 deg F. I believe there is some flexibility with the volumes. If I would have just added the drained quantity back, it would have been ~0.7 quart short. No difference in driveability however.