Pay for a flush? Or Drain and Fill?

[RF Overlord]

Originally Posted By: Trav
It has a 170K on it, usually the buyer of a car in this price class doesn't give a rats rear as long as it drives. LOL
This has more than a ring of truth to it, especially considering that:
Originally Posted By: dlundblad
Many folks still think ATF never needs changed unless there is an issue.


Personally, unless I have some physical record of a vehicle's maintenance, I always assume nothing's been done.

 

[DoubleWasp]

I've cooler line flushed transmissions that I know for a fact went well over 100k miles without service, and never had a trans drop on me. We did 13 trucks with OE trans fluid at 140-269k miles. Not one dropped it's trans.

The only 3 people I trust for transmission work tell me iit's an old wive's tale that originates in issues caused by fluid incompatibility, and trans sensitivity. With these new trans that have internal thermostats, it's also incompetence.

The thing people forget is that it's been scientifically proven again and again that contamination levels rise sharply after a flush is performed. If you're doing a flush, you should be adding a real filter to the transmission. I've used NZT filters, spin on externals, and Magnefine, and not had a problem after a flush.

Look at any transmission designed for the long haul, and you're going to find a spin-on filter, whether inside or outside of the pan. Rock catchers just don't do enough.

 

[ryanschillinger]

Fluid flows through the cooler lines anyway. As long as you aren't talking about a reverse power flush, there should be no problem doing the cooler line flush yourself.

 

[AKhan87]

Originally Posted By: pbm
I believe that Honda DOESN'T recommend power flushing.
this is true

Originally Posted By: pbm
I would do 3 D&R's 500 to 1000 miles apart.
this is close to what they recommend.

 

[Yah-Tah-Hey]

Do NOT let anyone flush your AT if it entails flushing with a solvent. I have read more than several horror stories about having ATs flushed.

 

[SatinSilver]

As mentioned, drain and fills spaced at least 500 miles apart.

 

[Trav]

Originally Posted By: AZjeff
Wouldn't it be nice if someone with a pedigree definitively answered the "flush ruined tranny" scenario? 1 example doesn't make every tranny flush a death sentence.

Not sure how a simple drain/fill could be anything but goodness.


If you call diluted dirty fluid goodness then i guess not. There is no such thing as a flush, no machine that i know of exist that back flushes the system, it is only a fluid exchange machine working in the direction of normal flow.

Most Japanese cars use hoses with clamps at the radiator so its no big deal to remove the return and let the transmissions pump do the job for you.
Let it pump till you see air bubbles then stop the engine and refill, repeat until the fluid coming out is the same as going in.
Fill the transmission to the correct level and that's the job done, i don't get all this Mickey Mousing around draining and filling just to end up with less dirty oil.
Would anyone change the engine oil a qt at a time?

If the transmission cant handle that it was on the edge of $hitting the bed anyway. Keep in mind that many people only service the transmission when it isn't working as it normally does, many times the fluid change is nothing more than a hail Mary pass.

 

[DoubleWasp]

Originally Posted By: Trav
Originally Posted By: AZjeff
Wouldn't it be nice if someone with a pedigree definitively answered the "flush ruined tranny" scenario? 1 example doesn't make every tranny flush a death sentence.

Not sure how a simple drain/fill could be anything but goodness.


If you call diluted dirty fluid goodness then i guess not. There is no such thing as a flush, no machine that i know of exist that back flushes the system, it is only a fluid exchange machine working in the direction of normal flow.

Most Japanese cars use hoses with clamps at the radiator so its no big deal to remove the return and let the transmissions pump do the job for you.
Let it pump till you see air bubbles then stop the engine and refill, repeat until the fluid coming out is the same as going in.
Fill the transmission to the correct level and that's the job done, i don't get all this Mickey Mousing around draining and filling just to end up with less dirty oil.
Would anyone change the engine oil a qt at a time?

If the transmission cant handle that it was on the edge of $hitting the bed anyway. Keep in mind that many people only service the transmission when it isn't working as it normally does, many times the fluid change is nothing more than a hail Mary pass.


People love the drain and fill because it involves the least amount of work in their eyes, and helps soothe the anxiety of believing the ancient rumors of proper flushes destroying transmissions.

Drain and fills do have their place, because as previously mentioned, some transmissions have internal thermostats that prevent a proper flush from being done. Ford's own manual for my transmission says there is no way to flush the transmission, and the dealer will simply not do it. I devised my own way to do it by taking down the filter, pushing a hose to the hole the filter goes into, and letting the transmission suck the fluid out of a bucket. Once clean fluid is running down into the drain pan I leave under the transmission, I reinstall the filter and fill the trans like normal.

Given that filling my transmission involves placing my hand in contact with the fire hot exhaust pipe (I use insulated gloves) with the engine running, there's no way I'm doing 3 drain and fills every 30k miles.

 

[Trav]

Yes some of the ones with internal thermostats can be a pain but i usually find a way around it. If it must be drain and fill its a lot of fluid and $$$ to get a full exchange.

 

[MolaKule]

Bear in mind here I believe a complete fluid replacement (via the cooler lines and using the AT pump for pumping) is the most efficient method of changing ATF.

Now, each to his own but Nissan and many other manufacturers recommends opening the drain plug and replacing the fluid via the dipstick at periodic intervals.

Since most Nissan AT's have no filter, and only a strainer, fluid changes are easy with them.

While the pan drain and refills are inefficient, and only replaces 1/4 to 1/3 the total fluid capacity, it does reduce the particle load, refreshes the additive package, and allows slow cleaning.

 

[268i]

Thanks everyone for the responses. At this stage im looking at doing a simple drain and fill. Genuine Honda ATF seems to be out of my price range and the nearest honda dealer is 20kms away.
I've read around "Valvoline Maxlife" is a good alternative. The local auto parts here in NZ don't seem to stock many type of ATF.

Anyone have an idea of the procedure? (Like shifting through all gears etc)

 

[Trav]

Nissan/Infiniti and IIRC Honda has a tech document for the dealer mechanics showing the correct line off exchange procedure. I will see if i can find it somewhere, I haven't seen it in a few years.

One of the reasons I don't like drain and fill outside of the obvious cost and waste of it is because of what you just said..
Originally Posted By: MolaKule
it does reduce the particle load, refreshes the additive package, and allows slow cleaning.

When you drain it and fill the increased cleaning ability further saturates the bulk of the already dirty worn out fluid.

Ideally draining the unit or pan, filling then at first restart letting the remaining old fluid out before it can recirculate and mix with the new fluid is really the best option.
The word "flush" is misused over and over again on this and other boards, it is better described as a vehicle assisted fluid exchange and is harmless.

I learned this back in 1971 in trade school and have been doing it ever since, to this day i have not lost one single unit after doing it this way. I still go though about 100 gallons of ATF a year so I am still doing a few transmission fluid exchanges.
If this were drain and fills you can multiply that by six to get the same result. The time and cost savings are enormous.

JM

That a 2 bucks will get me coffee.

 

[supton]

Originally Posted By: 268i
Thanks everyone for the responses. At this stage im looking at doing a simple drain and fill. Genuine Honda ATF seems to be out of my price range and the nearest honda dealer is 20kms away.
I've read around "Valvoline Maxlife" is a good alternative. The local auto parts here in NZ don't seem to stock many type of ATF.

Anyone have an idea of the procedure? (Like shifting through all gears etc)


Can't help you on the fluid.

If you are just doing a drain and fill, then I don't see a reason to go through the gears--it will work through anyhow. Or are you planning to drain, fill, then drain again within minutes?

 

[supton]

Originally Posted By: Trav

Most Japanese cars use hoses with clamps at the radiator so its no big deal to remove the return and let the transmissions pump do the job for you.

Let it pump till you see air bubbles then stop the engine and refill, repeat until the fluid coming out is the same as going in.
Fill the transmission to the correct level and that's the job done


If you get bubbles, isn't the pump run dry, and thus it's a bad thing?

I'm tempted to try this again on my truck, but it was such a pain the last time I've been using every excuse to not to. It would be a pinch easier if I could do that, get a clear bucket and measure what comes out.

 

[MolaKule]

Quote:
...The word "flush" is misused over and over again on this and other boards, it is better described as a vehicle assisted fluid exchange and is harmless....


For sure. The word has both been misused and misunderstood.

Quote:
When you drain it and fill the increased cleaning ability further saturates the bulk of the already dirty worn out fluid.


I have to gently disagree here with my collegue as there is no "saturation" of solids after each pan drain and refill.

A fluid analysis after each pan drain and refill will show a reduction of at least 20-35% of solids, as did my three analyses of the Frontier's ATF analysis.

Quote:
Ideally draining the unit or pan, filling then at first restart letting the remaining old fluid out before it can recirculate and mix with the new fluid is really the best option.


Agreed, and as I stated earlier, this is the most efficient method for completely exchanging the ATF.

 

[wobbie]

I bought a Mazda 3 with 110km without checking the trans fluid. Once I got it home I was surprised - it looked like motor oil, I had never seen ATF that dark. Frankly, I thought I was doomed. [yes I know the difference in the dipsticks]

Figured with a total capacity of about 12l, I did a drain and fill of about 3l so that was about 25% of the contaminant load. Next day did another which should remove 25% of the remaining 75% so about 19% of the initial load - then another.

So, I figured I too out 25% + 19% + 11% for a total of 55%. Fluid looked relatively pink.

Drove it to 195km, dropped the pan and did a filter change, clean magnet and still looks pretty good. I'll get a nice day sometime soon and drop the pan again to clean the magnet and another drain and fill.

So far still shifting fine.

Now I should mention the Mazda 2.3 does have a drain plug, and yes I am very careful on my refill to watch my "full hot" marks.

 

[meborder]

Originally Posted By: DoubleWasp


I devised my own way to do it by taking down the filter, pushing a hose to the hole the filter goes into, and letting the transmission suck the fluid out of a bucket. Once clean fluid is running down into the drain pan I leave under the transmission, I reinstall the filter and fill the trans like normal.



I had forgotten about this until you wrote down your procedure. My brother worked at a Pennzoil quick change station for a while and this was the method they used to do transmission service.

they had a slightly fancier setup, but the basics of it was exactly as you described. they would always "burn" a couple extra quarts above the listed capacity to ensure a complete fluid exchange, since you do lose a bit of the new fluid at the beginning of the exchange.

I would highly recommend this type of procedure to anyone that needs to do a fluid exchange as a DIY way for a vehicle with a thermostatically controlled transmission.

Thanks for posting!

 

[AKhan87]

Originally Posted By: supton
Originally Posted By: Trav

Most Japanese cars use hoses with clamps at the radiator so its no big deal to remove the return and let the transmissions pump do the job for you.

Let it pump till you see air bubbles then stop the engine and refill, repeat until the fluid coming out is the same as going in.
Fill the transmission to the correct level and that's the job done


If you get bubbles, isn't the pump run dry, and thus it's a bad thing?

this is my main concern too, running things dry, so can someone clear this up for me?

using a transmission cooler line, start car and let it drain until bubble, and run & turn off the car immediately? this is where I'm confused, by doing this, wouldn't it run it dry and cause some sort of damage? I never could get past this question to even attempt it, if this truly causes no damage in a Toyota transmission, I would love to do this in all my cars, as fresh fluid would be the best route.

Then repeat this process until the fluid coming out of the cooler line is same as new?

 

[cjcride]

01Celica you could have a helper shut the engine off on your hand signal.
Nothing in the the transmission will be 'Dry Instantly'.

I have not done the transmission line flush myself yet have researched it and may do my next D&F that way.

 

[ryanschillinger]

When I did the cooler line flush on my Corolla and the Camry I used to have, I ran the clear hose over the core support so I could see as soon as it started to bubble. No helper needed. I ran the fluid into an empty clear gallon water container to know where I sat relative to a gallon of fluid. 3 gallons is plenty to flush the transmission. Just make sure to test drive after and check fluid hot and put it at the correct level.