Tranny Fluid Flush Calculator

turbochem · Apr 16, 2003

I know alot of people on this board want to change 100% of their fluid in their transmission. But, when doing a flush or dropping the pan, they can only change a certain amount of fluid....never 100%

Well, for those die-hards who have to have 100% fresh transmission fluid, I have created a simple little spreadsheet do-hicky to figure out how many times you'd have to change your fluid in increments (# of pan drops, or additions of fluid) to get 100% (actaully, approaching 100%) new fluid.......

Transmission Calc

Note: The calculator assumes that the fluid is a homogeneous mixture of old/new fluid through out the transmission after adding the new fluid. Hey, you need assumptions......

Ken4 · Apr 16, 2003

Cool! I only need 9 changes for my Toyota Camry.

dkcase · Apr 16, 2003

Nice Work....

digitaldrifter91 · Apr 16, 2003

someone has alot of time on their hands, but its interesting. i have to do about 5. now you got me thinking, if i used my regular vacumn for the house with a waterbased dirt retainer, can i get more out? good stuff! now i have something to play with for a while hehe.

Butch 02 Sierra Denali · Apr 16, 2003

Hey Turbochem, nice work! I can see you put alot of effort into it. For an alterative and much easier way to get 100% change, disconnect the cooler return line, start the vehicle and pump out 2 qts, shut off, add 2 qts, and repeat until you see clean fluid come out, for a 4L60 that is about 12 qts. You will get 100% new fluid and not even have to crawl under the vehicle, although I would reccomend a filter change as the first step!

Butch 02 Sierra Denali

outrun · Apr 17, 2003

Simpler Solution (for those that will pay for it)

Go to a Dealer or a well rounded service center. Ask for the Trans-Tech or BG Transmission Flush Service w/new ATF filter service.

A)They remove and clean the pan, replace the gasket if applicable and put a new strainer filter. Also, a good opportunity to see the solids that turn up thier and sludge levels.

B)After replacing the pan they fill it up with the bargain cheapo ATF to top-off to normal.

C)Then they disconnect both cooler lines and attach it to a machine filled with 2 resovoirs. One resovoir for the intake of used ATF and the other filled with whatever ATF of your choosing.

D)They turn the engine on and the ATF high pressure line spurts of the used fluid into the machine while the low pressure line inhales the new stuff.

So if your not a DIY'r there is no excuse for the traditional pan and service changes. I am of the skewl of thought that thinks why contaminate 5qts of new synthetic ATF to 8 or so quarts of potentially ATF so old it dates back to the factory.(IMO) And by the way, vehicle assembly assembly lines DO use mechanical infusers of ATF for the original factory fill.

Do it once and for all...do it right.

digitaldrifter91 · Apr 17, 2003

you stated:
"D)They turn the engine on and the ATF high pressure line spurts of the used fluid into the machine while the low pressure line inhales the new stuff."

i got a quick question. i didnt know that the low pressure line had pressure. i thought that the high pressure from the transmission just made its way to the other line that goes back to the transmission. if so, then i can just put the low pressure tube in a bottle of ATF, and then let the other returning fluid drain into a bucket?

or am i completly wrong and stupid =).

...how much is t-tech without the pan drop? (i have no filter and no pan to drop).

outrun · Apr 17, 2003

drifter dude,

Okay i admit i am over my head in answering that specific question?? Technically I would call it a low pressure line since the cooler return line is not at the same fluid velocity as the one coming from that of the Torque Convertor.

After all its TQ(high volume)---ATF line(area constriction, ++pressure)---INTEGRAL COOLER (lots of volume and hence a - pressure drop)---ATF return line (lower pressure than initial)

My reasoning.

Obviously even in this machine service SOME MIXING of new-fluid will inevitably occur! (Kind of like a a reptilian heart that has not evolved a true barrier between oxygenated and venous blood and hence the two mix in minutia)

Except for a full scale tea not every drop, molecule and what will be virgin ATF whatever process you use. *LOL* of course the new ATF will immediately get to work libertaing all that sludge quite fast, so prompt contamination is inevitable

BG claims the service to transfuse at least 95% new ATF over the 25% of conventional drop your pan services.

Cost?

Dealer charges $125-135 I have seen

Goodyears $120

Pep Boys is 115$ (if ya actually trust them enough)

This cost will include a new ATF gasket and filter + 12qts of make-up fluid. I would assume those that go ahead and do this service from the forum will go ahead and supply the dealer with thier own Redline, M1, Shaeffers, AMSOIL, RP premium stuff or for the replacement. Knock of about 30-50$ if you supply your own ATF and more if you bring your select ATF filter(s) and gasket.

If you read into Frank's AUTO-RX site he does recommend using an ATF transfuser-flushing machine service in conjunction with the prescribed use of the Trans-Medic product. His personal credibility has already been well established here.

digitaldrifter91 · Apr 17, 2003

hehe thanks for answering. i guess i wont truely know until i do it myslef. i am following franks sugustion on his method, i have some auto rx in there now as well. next time ill go with t-tec...i ran out of cash =).

Butch 02 Sierra Denali · Apr 17, 2003

Hey guys,
Just to clarify, the fluid comes from the pan thru the filter and to the pump, and follows multiple paths thru the transmissions valves and torque converter. All the fluid is returned to the pan thru the cooler line, no other path returns any fluid to the pan. The cooler line is pressurized at transmission line pressure, if you seperate the line to do a 100% change, the return side of the line is not a vacuum source, it just flows back into the transmission pan.
I prefer to do it myself,no driving to a shop and waiting and worrying that they are going to mess it up or scratch my truck. It's easy, the only cost is 12 qts of fluid @$1.25= $15, and less than an hours work, including clean-up. I'll take the 100 bucks I save and put it in my supercharger fund!

Butch 02 Sierra Denali

turbochem · Apr 17, 2003

Yeah, the Flush through the Transmission/Pourd through dip stick line is the easiest and cheapest way.....that's how I do it (not that my enorsement will make it fad or anything).

Luckily, my Volvo ('84 240 Turbo) uses a one of those metal screen transmission filters (more like a soup strainer) so I don't even have to drop the pan!!

And no machine to pay for........

unDummy · Apr 17, 2003

Flush machines are nothing but a new profit maker for dealers/garages.

I've seen some skip the pull pan/replace filter/refill prior to the actually flush. They just "splice/flush/topoff". So, using the word "trust" is for every shop out there.

You can flush the fluid by yourself without the machine. Disconnect cooler output, attach line, aim into bucket, start vehicle. Shut off and top off as needed in premeasured increments.

outrun · Apr 18, 2003

In reference to your concern of bogus shops?

Yes, that is a very plausible conclusion that they are around everywhere.

In my case I have been fortunate to build lasting friendships with those that work on my car. In addition I have the time to sit down and actually observe the techs working on my car.

Likewise, when I had the T-Tech service performed on my trans I watched the whole process from pan, removal and cleaning to refill and recharge with the synthetic blend ATF.

No frauds here. However your cautionary remark to others is well taken.

Benzadmiral · Aug 31, 2007

Will this calculator work for smaller things like a power steering system/reservoir? Much smaller volume?

unDummy · Aug 31, 2007

yep, it'll work for any fluid measurement.

Donald · Sep 3, 2007

So if one had really bad looking fluid in the AT and wanted to go to synthetic, when you look at drain and refills vs a flush, here are the financials (Amsoil = $9/QT from their website).

My Camry takes 5.9QTs total and 2.6QTs in a drain and refill.

To get to 95% new fluid would take 8 drain & refills or 20 QTs of new fluid. Thats $180 just for Amsoil ATF. The cost to fill the AT with Amsoil (6 QT) would be $54. Throw in another QT to be sure and we are at $63. One should be able to get a flush done for $100 if you supply the fluid. So its cheaper to go to a shop to have a flush done to change out really bad fluid to synthetic. If you do the flush yourself, then you are way ahead doing a flush vs 8 drain & refills.

shoz123 · Sep 4, 2007

Quote:

Hey guys,
Just to clarify, the fluid comes from the pan thru the filter and to the pump, and follows multiple paths thru the transmissions valves and torque converter. All the fluid is returned to the pan thru the cooler line, no other path returns any fluid to the pan. The cooler line is pressurized at transmission line pressure, if you seperate the line to do a 100% change, the return side of the line is not a vacuum source, it just flows back into the transmission pan.

On my Ford Taurus I have on more than one occasion failed to tighten down the hose clamp on the cooler line after doing a flush.

Once drove 200 miles at highway speeds on the interstate. It did finally come off while driving around town though. But the pressure in the cooler lines is no where near line pressure. The EPC on my car will reach 130 lbs at a WOT shift and normally sees 30-50 lbs while cruising. This is not the pressure coming out of the line when I do a flush.

I follow the Ford method described in their shop manuals of pumping it out until the flow almost stops, then drop the pan and change the filter, then add 10 quarts, then pumping it out again until it almost stops or the fluid is new looking. Then top off with the 4-6 quarts it needs to reach the proper level.

benjamming · Sep 10, 2007

could this be made a sticky?

mikeg5 · Sep 10, 2007

for you guys who pull the cooler line and drain over 1 qt at a time while the engine/transmission is running arent you playing with fire? doesnt most transmissions mess up when you run it 2qts low? the way i was told was to drain 1 QT at a time. yeah thats a lot of starting and stoping but its less likely to get air pockets and also less likely the transmission will overheat..

unDummy · Sep 11, 2007

No, you're not playing with fire because there are no air pockets since you are NOT driving the car and it will NOT overheat without a load.

Tranny Fluid Flush Calculator

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