2002, V70 (ATF Drain) Topic is solved

[Mr. Detail]

Thanks vtl. That basically answers my question.

[Mr. Detail]

If the oil is very contaminated not even 30l will clear it out completely, I am speaking from experience.

I’ve done two Volvo Aisin automatics via the transmission cooler return flush method and each took right at 12 quarts for the fluid to be pink and clear.

Krons, is the method you speak of here "transmission cooler return flush method" different from what I spoke of? Just the sump drain.

[vtl]

Krons, is the method you speak of here "transmission cooler return flush method" different from what I spoke of? Just the sump drain.

Transmission diverts only a small fraction of ATF flow to the cooler, the rest goes back to sump. In my experience the Gibbons method is more messy and more risky (bubbles in ATF is no good for oil pump nor clutch packs), and offers no benefits over drain and fill.

[MoVolvos]

If the oil is very contaminated not even 30l will clear it out completely, I am speaking from experience.

I’ve done two Volvo Aisin automatics via the transmission cooler return flush method and each took right at 12 quarts for the fluid to be pink and clear.

Krons, is the method you speak of here "transmission cooler return flush method" different from what I spoke of? Just the sump drain.

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I believe Kron is referring to the method in the videos. Lost count of how many I've done. If you do a chart on contaminated fluid percentages using the drain and fill method you'll see it's really not beneficial at all.

Every time someone says the flush method will do damage it's I heard or it may, then proceed to give all sorts of reasons why. Never seen an example of damage taking place in an article, post, video etc... Instead of pumping two liters out I've always pump till no fluid comes out of the tube and quickly shut off engine then fill the pan and repeat.
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[Krons]

If the oil is very contaminated not even 30l will clear it out completely, I am speaking from experience.

I’ve done two Volvo Aisin automatics via the transmission cooler return flush method and each took right at 12 quarts for the fluid to be pink and clear.

Krons, is the method you speak of here "transmission cooler return flush method" different from what I spoke of? Just the sump drain.

It is different than the simple sump drain. As shown in the videos, it is pulling the transmission cooler return to run a hose to a jug and use the transmission to pump out about 2 qt at a time. I would not run it dry like some of the videos show.

This one shows the transition from dirty to clean fluid on a Volvo.


As the comments show some disagreement on best method—but if the goal is to completely change the fluid (switching brands, etc) I feel this is the most complete way to do it based on the change in fluid color through the process.

[MoVolvos]

I’ve done two Volvo Aisin automatics via the transmission cooler return flush method and each took right at 12 quarts for the fluid to be pink and clear.

Krons, is the method you speak of here "transmission cooler return flush method" different from what I spoke of? Just the sump drain.

It is different than the simple sump drain. As shown in the videos, it is pulling the transmission cooler return to run a hose to a jug and use the transmission to pump out about 2 qt at a time. I would not run it dry like some of the videos show.

This one shows the transition from dirty to clean fluid on a Volvo.


As the comments show some disagreement on best method—but if the goal is to completely change the fluid (switching brands, etc) I feel this is the most complete way to do it based on the change in fluid color through the process.

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If there is a concern for running the pan dry for a split second, just remove all the fluid in the pan at the beginning. I have an oil extractor which pretty much removes everything in the pan.

Regardless of method, whether run dry for split second or 2 quarts at a time don't mix 2 quarts of clean with 2 quarts of dirty remaining in the pan at the beginning. At that point you're continuing to dilute the dirty fluid. Remove everything in the pan in the beginning and you'll be adding 2 quarts to clean fluid each time.
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[vtl]

Regardless of method, whether run dry for split second or 2 quarts at a time don't mix 2 quarts of clean with 2 quarts of dirty remaining in the pan at the beginning. At that point you're continuing to dilute the dirty fluid. Remove everything in the pan in the beginning and you'll be adding 2 quarts to clean fluid each time.

No. Old fluid is dripping to sump from everywhere, you can not prevent that. You'll be adding 2 quarts to new/old mix.

[Krons]

Regardless of method, whether run dry for split second or 2 quarts at a time don't mix 2 quarts of clean with 2 quarts of dirty remaining in the pan at the beginning. At that point you're continuing to dilute the dirty fluid. Remove everything in the pan in the beginning and you'll be adding 2 quarts to clean fluid each time.

No. Old fluid is dripping to sump from everywhere, you can not prevent that. You'll be adding 2 quarts to new/old mix.

vtl I know you disagree but this is my experience…

Start by draining 3+’ish quarts and filling sump back up. That first pump out via the cooler return in my experience is filthy with little indication of fresh fluid in it. Like the video I posted shows it progressively gets cleaner.

Logic tells me by only doing a drain and fill process it’ll take more fluid to get it clean. We may disagree but in the end either process works to get fresh fluid into the system.

[MoVolvos]

Regardless of method, whether run dry for split second or 2 quarts at a time don't mix 2 quarts of clean with 2 quarts of dirty remaining in the pan at the beginning. At that point you're continuing to dilute the dirty fluid. Remove everything in the pan in the beginning and you'll be adding 2 quarts to clean fluid each time.

No. Old fluid is dripping to sump from everywhere, you can not prevent that. You'll be adding 2 quarts to new/old mix.

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If you can drain the fluid through a plug in the pan and you empty 3.5 quarts, you'll wind up putting in fresh 3.5 quarts into the empty pan. Now, if you flush through the radiator transmission hose, all 3.5 quarts will be pumped into the system while 3.5 quarts come out of the hose.

There will be dripping from inside the pan but not 2 quarts. Have done so many of these on so many makes. I always flush through an extra 2 quarts of the system capacity but it's usually clean after the 1 extra quart.
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[vtl]

If you can drain the fluid through a plug in the pan and you empty 3.5 quarts, you'll wind up putting in fresh 3.5 quarts into the empty pan. Now, if you flush through the radiator transmission hose, all 3.5 quarts will be pumped into the system while 3.5 quarts come out of the hose.

There will be dripping from inside the pan but not 2 quarts. Have done so many of these on so many makes. I always flush through an extra 2 quarts of the system capacity but it's usually clean after the 1 extra quart.

I wrote it perhaps a zillion times here and in other Volvo forums, that heat exchanger gets only a small fraction of all ATF circulating in the system. Everything else goes back to sump. It is not like you take out 2 dirty quarts, put 2 fresh quarts and it never mixes with dirty ATF left in the system. Even if you drain the sump first and refill it with fresh ATF, doing the rest through heat exchanger does not prevent old/new ATF mixing up.