Nissan CVT - Advantages of Drain/Fill vs. Pumping out through transmission cooler?

I just picked up an 09 Versa SL (1.8L/CVT) and am looking to replace the CVT fluid. I've already picked up the OEM Nissan CVT fluid from the dealer, my only question is which method the hive would follow.

I saw a YouTube video of a similar year CVT Sentra where someone did a simple drain/fill/top off. My setup looks identical to his (same dipstick, same drain plug), so I think this method would work equally well for the Versa.

I looked it up in the Factory Service Manual and they recommend disconnecting the CVT fluid cooler hose and running the engine at idle to pump the fluid out while adding new fluid through the transmission dipstick until the fluid coming out of the hose looks new.

Are there any significant advantage/disadvantage with either method?

I'm thinking the the Factory Service Manual method would get more of the older fluid out than the drain/fill method, at the expense of using slightly more fluid. I was going to mark off a gallon jug so I could try to add the fluid at roughly the same rate it's being removed.

this is my first CVT, so I'm trying not to screw it up the second day Any tips from those who know better? Thanks!

My sons 2007 Sentra has the CVT and the factory extended the warranty since they had issues. Check with your dealer. If so ask them about changing the fluid?

I haven't dealt with a CVT before, but for normal auto transmissions I like to do a full drain/fill with the cooler lines when I first get it, and then do a drain/fill of just the pan every oil change or two.

In reply to dj06482:

I would start with a normal drain, then see how much you got out. Check that against the total system capacity. I put in 3L against a total capacity of 4L in my Honda CVT. Seems like a high enough ratio to me, but you might get better out of yours. Or not, in which case you can use the other method. I change it every other oil change for good measure (soon to become every oil change due to slippage).

I also believe a drain and fill should be sufficient. You could also gauge the condition of the old fluid that comes out. If it's dark/dirty, then take it a step further with a flush.

I'm not familiar with CVT but if it's anything like a normal auto and has a pan, I'd rather do pan drops to scrape the sludge out of the pan, clean the magnets, and inspect the filter than just pump it out, though you'll want to drop the pan more often than a full exchange since you aren't gettign all the old fluid out. If it doesn't have a pan, I'd still rather do a drain and fill twice as often (assuming it loses half its fluid in a drain, adjust accordingly) as berkeleying around with the cooler lines.

We always just drop the pan, for two reasons.

1. It's not like there's a torque converter to hold a bunch of fluid. You DO get most of the fluid with a simple pan drop.
2. We'd have to change the fluid in our fluid exchange machine and that is a major PITA.
3. CVT juice can be QUITE expensive!

Three. Three reasons... Amongst the reasons why we just do a pan drop are such diverse reasons as:

You know, I'll come in again.

I couldn't find the info on the pan drop quickly enough (especially the torque specs), so I did a simple drain and fill. Just under 5.5 qts came out, and the new fluid looked good on the dipstick, so I stopped after a single drain/fill.

I'll have to look into what gasket (if any) is used and what the torque specs are for the bolts. I'm also interested if there's any filter to be replaced when I'm in there next.

It does have a torque converter, so you only got maybe a bit over half of it out. I believe there is a gasket for the pan - one of those thin metal type ones, not graphite. There is a filter built into the oil pickup.

Run_Away wrote: It does have a torque converter, so you only got maybe a bit over half of it out. I believe there is a gasket for the pan - one of those thin metal type ones, not graphite. There is a filter built into the oil pickup.

Thanks for the confirmation. I was planning to do at least a drain/fill with the next oil change, but I'm going to look into dropping the pan, as well.