Transmission drain & refill

[momomeister]

In the newer Honda's, if you do a drain/refill 3x, you've basically replaced 85% of the ATF.

Just find the total capacity and see how much comes out of each drain. If each drain is roughly 30%, you'll be at roughly 85% new fluid. Going for a 4x drain refill, you basically replaced 90% of the ATF.

 

[MK2]

The manual says its 6.2 quarts for overhaul.

 

[crinkles]

give it 1,000 miles between back to back drain and fills to mix well. I only had to do it twice and always looks brand new now.

 

[Donald]

Originally Posted By: momomeister
In the newer Honda's, if you do a drain/refill 3x, you've basically replaced 85% of the ATF.

Just find the total capacity and see how much comes out of each drain. If each drain is roughly 30%, you'll be at roughly 85% new fluid. Going for a 4x drain refill, you basically replaced 90% of the ATF.


Check your math, while the first drain might be 30%, each one goes down in the percentage it raises the total percentage new fluid. Towards the end, you only gain a few percent per drain and refill.

 

[FZ1]

I drain and refill 1x per year. Figure that keeps it fresh enough.

 

[MK2]

Hhhmmm still undecided; drain and refill is more easier and cheaper for me, but will cost more in the long run. And I'm bit worried about the ATF's color right now, I might post some pics to give you guys and idea.

Thanks

 

[benjamming]

The color isn't a good indicator of anything other than the dye is fading. A UOA is a cheap & simple way to know.

 

[hate2work]

Originally Posted By: benjamming
The color isn't a good indicator of anything other than the dye is fading. A UOA is a cheap & simple way to know.


Not sure I agree with this, at least on a practical basis.

Color is at least a decent indicator of the age, if not the quality, and therefore provides at minimum a clue as to the life of the fluid. If someone has questionable ATF I would not recommend sending off and then waiting for a UOA, that would be silly IMO. In one hour or less the fluid could be drained and refilled twice, and in the meantime you could send for an analysis if you really wanted to know.

OP, what does the fluid smell like? A burnt odor usually means bad things.

 

[Donald]

I think the answer is if its bright red is almost certainly in good shape. But if its not it may or may not be in good shape. Some transmissions dirty the oil up quickly and still in decent shape. I agree that a UOA is the only way to know for sure. But pulling a sample is a pain without a sample pump (how many people have a smple pump), and if you are deciding what to do, then most likely you are not draining the ATF (yet).

Feeling for grit, smelling and smearing some on a new white coffee filter may also give some indications.

 

[hate2work]

Originally Posted By: crinkles
give it 1,000 miles between back to back drain and fills to mix well. I only had to do it twice and always looks brand new now.


1000 miles? That's a bit much methinks

When doing back to back drain and refills, it's pretty easy to tell it's fairly well mixed even if you only drive around the block a couple of times.

 

[Donald]

I was thinking the pump might do 1 PT per minute, (my guess) so that would be my 8 QTs in 15 minutes or 4 changes/hour.

This is based upon a tiny observation of a hose shoved into a empty water bottle checking the flow direction while installing a Magnefine filter.

I think a drive around the block might not be enough, but 1 hour of driving should be.

 

[benjamming]

A UOA is silly huh. So, knowing the facts is worse than guessing, wow. If you can't wait a week for a UOA, it's already way too late for new fluid to do anything for you.

According to Honda, color is not to be used as an indicator of fluid quality. Color is not an indicator of age other than it wasn't changed this morning type of thing. Some ATF "lose their dye" sooner than others.

Smell is cited way too often by folks since each ATF brand can smell differently. Many people will think that practically new ATF smells bad.

Bad data = wrong conclusions.

 

[Donald]

I was thinking the pump might do 1 PT per minute, (my guess) so that would be my 8 QTs in 15 minutes or 4 changes/hour.

This is based upon a tiny observation of a hose shoved into a empty water bottle checking the flow direction while installing a Magnefine filter.

I think a drive around the block might not be enough, but 1 hour of driving should be.

 

[Blokey]

Originally Posted By: benjamming
Many people will think that practically new ATF smells bad


OMG, have you taken a whiff of Amsoil ATF lately?? It smells almost as bad as gear oil.

 

[hate2work]

Originally Posted By: benjamming
A UOA is silly huh. So, knowing the facts is worse than guessing, wow. If you can't wait a week for a UOA, it's already way too late for new fluid to do anything for you.

According to Honda, color is not to be used as an indicator of fluid quality. Color is not an indicator of age other than it wasn't changed this morning type of thing. Some ATF "lose their dye" sooner than others.

Smell is cited way too often by folks since each ATF brand can smell differently. Many people will think that practically new ATF smells bad.

Bad data = wrong conclusions.


UOA is silly? Well, that's not exactly what I said. What I said was that if you had questionable ATF, I would not recommend waiting while you sent off for a UOA. That's quite different than what you implied that I said. Nice try, though.

The color of ATF has been and will continue to be one indicator of the quality of the fluid. Is it the best indicator? Probably not, but I never claimed that to be the case, did I? Does that make it an invalid test? Hardly.

You ever smell any new ATF that smelled burnt? Yeah, that's what I thought. Once again, your argument doesn't hold water.

But thanks for writing back, at least that shows you're TRYING to understand.

 

[crinkles]

Originally Posted By: hate2work
Originally Posted By: crinkles
give it 1,000 miles between back to back drain and fills to mix well. I only had to do it twice and always looks brand new now.


1000 miles? That's a bit much methinks

When doing back to back drain and refills, it's pretty easy to tell it's fairly well mixed even if you only drive around the block a couple of times.


well at least you get some use out of the fresh fluid. the 30% new can be used for 1000 miles before dumping out. Why dump that new fraction after 2 miles? effect is the same and you spread your costs. i waited 5,000km between my drain and fills.

 

[hate2work]

Originally Posted By: crinkles
Originally Posted By: hate2work
Originally Posted By: crinkles
give it 1,000 miles between back to back drain and fills to mix well. I only had to do it twice and always looks brand new now.


1000 miles? That's a bit much methinks

When doing back to back drain and refills, it's pretty easy to tell it's fairly well mixed even if you only drive around the block a couple of times.


well at least you get some use out of the fresh fluid. the 30% new can be used for 1000 miles before dumping out. Why dump that new fraction after 2 miles? effect is the same and you spread your costs. i waited 5,000km between my drain and fills.


I completely agree with you, in most cases a single drain and refill is all that's needed, especially if you're on a regular maintenance schedule. But doing the back to back D and R is the way to go for neglected transmissions.

Plus there is the convenience factor. It's just as easy to do a D and R, drive for a bit, then do it again right away while your ramps, tools, etc., are still out.

And if you're switching to synthetics, and you don't want to do a complete flush, back to backs will get more of the good stuff in there faster

 

[benjamming]

Originally Posted By: hate2work

UOA is silly? Well, that's not exactly what I said. What I said was that if you had questionable ATF, I would not recommend waiting while you sent off for a UOA. That's quite different than what you implied that I said. Nice try, though.

The color of ATF has been and will continue to be one indicator of the quality of the fluid. Is it the best indicator? Probably not, but I never claimed that to be the case, did I? Does that make it an invalid test? Hardly.

You ever smell any new ATF that smelled burnt? Yeah, that's what I thought. Once again, your argument doesn't hold water.

But thanks for writing back, at least that shows you're TRYING to understand.


I still believe that color is one of the most overused & abused indicators of quality.
I didn't say that smell can't be used but that it is often abused as well. It doesn't seem to be abused as much as the color theory.
Again, if the fluid is so bad that waiting on a UOA is going to cause more problems, of course you don't need a UOA to determine if it should be changed. However, you do need a UOA to determine what the subsequent OCIs should be & what caused the fluid to go south so badly. Sometimes there are mechanical problems that need to be addressed. There is also the possiblity that the wrong fluid may even the culprit which a UOA will also highlight.

BTW, I wasn't trying to imply anything that you didn't say.

 

[Donald]

Originally Posted By: hate2work
Originally Posted By: crinkles
Originally Posted By: hate2work
Originally Posted By: crinkles
give it 1,000 miles between back to back drain and fills to mix well. I only had to do it twice and always looks brand new now.


1000 miles? That's a bit much methinks

When doing back to back drain and refills, it's pretty easy to tell it's fairly well mixed even if you only drive around the block a couple of times.


well at least you get some use out of the fresh fluid. the 30% new can be used for 1000 miles before dumping out. Why dump that new fraction after 2 miles? effect is the same and you spread your costs. i waited 5,000km between my drain and fills.


I completely agree with you, in most cases a single drain and refill is all that's needed, especially if you're on a regular maintenance schedule. But doing the back to back D and R is the way to go for neglected transmissions.

Plus there is the convenience factor. It's just as easy to do a D and R, drive for a bit, then do it again right away while your ramps, tools, etc., are still out.

And if you're switching to synthetics, and you don't want to do a complete flush, back to backs will get more of the good stuff in there faster


Why do back to back drain and refills when a cooler line flush will exchange above 90% of the fluid for close to the same about of fluid used in two drain and refills. Make no sense to me if you have easy access to the cooler lines.

 

[hate2work]

Originally Posted By: Donald
Originally Posted By: hate2work
Originally Posted By: crinkles
Originally Posted By: hate2work
Originally Posted By: crinkles
give it 1,000 miles between back to back drain and fills to mix well. I only had to do it twice and always looks brand new now.


1000 miles? That's a bit much methinks

When doing back to back drain and refills, it's pretty easy to tell it's fairly well mixed even if you only drive around the block a couple of times.


well at least you get some use out of the fresh fluid. the 30% new can be used for 1000 miles before dumping out. Why dump that new fraction after 2 miles? effect is the same and you spread your costs. i waited 5,000km between my drain and fills.


I completely agree with you, in most cases a single drain and refill is all that's needed, especially if you're on a regular maintenance schedule. But doing the back to back D and R is the way to go for neglected transmissions.

Plus there is the convenience factor. It's just as easy to do a D and R, drive for a bit, then do it again right away while your ramps, tools, etc., are still out.

And if you're switching to synthetics, and you don't want to do a complete flush, back to backs will get more of the good stuff in there faster


Why do back to back drain and refills when a cooler line flush will exchange above 90% of the fluid for close to the same about of fluid used in two drain and refills. Make no sense to me if you have easy access to the cooler lines.


Of course it makes no sense to you, because you're thinking like someone who knows how to do that job. But many people have never done that/ don't feel competent enough to do that, and for those people, back to back drain and refills makes perfect sense.

Does that make sense?