ATF Drain & Fill : How To Remove Max Fluid ?

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I understand that to remove the max ATF for a drain & fill process (without disconnecting hoses) - with the engine running you shift from D to P or D to R to P in order to get max fluid flowing through the torque converter which in turn gets the most fluid to drain . *My question is do you do this sequence before you release the ATF drain plug below OR do you perform this sequence with the engine running and the ATF drain plug removed ? I want to get the max fluid out during a ATF drain and fill but of course do not want to hurt the transmission ... Thanks in advance for replies .
 
You don't want to start the car with the AT pan empty. The max you can get out without getting a little more serious about it is to drain the pan.

if you want to do a good fluid swap, pull a hose and catch the dirty fluid heading to the pan while keeping the pan topped-up.
 
I wouldn’t shift through gears during a fluid change.

And exchange is the best way IMO, but if there’s a filter to replace, I’d do that too.

Just to echo the above, get some clear containers and make some “1 quart” graduated lines or use oil jugs with the clear site area. That’ll help you know what’s going on fluid wise. 1 quart in, 1 out something like that. Depending on the vehicle, a clear 5 gallon bucket would even work with 2-3 quart graduations.

Get a helper to hand you the quarts, open lids, remove foil etc. Get everything ready beforehand and take your time. Get some fuel hose to slide over the cooler line and run to the waste containers.
 
What's wrong with disconnecting hoses?

On my car it was one allen screw and two o-rings.

Got all the fluid.

IMG_20191029_223709.jpg
 
To the OP: removing the drain pan and filter (if applicable) and letting the vehicle sit overnight will allow the most fluid to drain in the manner you described.
 
I don't believe there's any connection between your transmission pumping fluid to the valve body (to execute your shifting) and what's sent to the TC.
A) I've been doing drain & fills and pump-outs for years as well as reading threads on the subject. Nobody has ever offered any description of how a torque converter has fluid delivered to it or how one drains.

B) After a pump-out to clear red I've seen the fluid regain a dark tinge within a week. I always assumed this was dirt in the TC or elsewhere going into solution.

C) When I do a pump-out I do a drain & fill first so I'm not adding clean fluid to dirty sump fluid. The pump-out starts with sucking up clean fluid.
This is as "nit-picky" as I get.
 
I don't believe there's any connection between your transmission pumping fluid to the valve body (to execute your shifting) and what's sent to the TC.
A) I've been doing drain & fills and pump-outs for years as well as reading threads on the subject. Nobody has ever offered any description of how a torque converter has fluid delivered to it or how one drains.

B) After a pump-out to clear red I've seen the fluid regain a dark tinge within a week. I always assumed this was dirt in the TC or elsewhere going into solution.

C) When I do a pump-out I do a drain & fill first so I'm not adding clean fluid to dirty sump fluid. The pump-out starts with sucking up clean fluid.
This is as "nit-picky" as I get.

 
My suggestion would be to NEVER dry sump the ATF by draining all the fluid out and then trying to get "more" out by running the engine, running it through the gears, etc. Just follow the OEM method (Drain and fill) that can be seen in the PDF files of your model year car online.
 
LubeFiner: Thanks for the link to TC operation. It did not show how fluid enters the TC nor did it show how TC's leak down upon shutdown.

I know there were older VW torque converters which would leak down to the 6 o'clock position of the central shaft hole. I also know there were Ford TC's with a drain plug. On those you'd touch the starter to get that plug to 6 o'clock and unscrew it to drain the TC.
Either design feature makes for a more thorough drain.

Posters continually ask about getting the last bit of fluid out during a drain. This spawns bad ideas like running the engine with an empty trannie sump.
Diluting the dirt with drain & fills or pumping out old fluid whilst replacing with fresh is all one can do to get fluid clean.
 
My suggestion would be to NEVER dry sump the ATF by draining all the fluid out and then trying to get "more" out by running the engine, running it through the gears, etc. Just follow the OEM method (Drain and fill) that can be seen in the PDF files of your model year car online.

Any basis for that statement? I often start the engine and put it through the gears after the pan is empty. Usually get another half quart out. It's not like running an engine without oil so there isn't any cushion between the bearings. I only run it 10 or 15 seconds so the coating of transmission fluid still on the parts prevents any damage.
 
After further reading it appears best to idle , apply brake , cycle through the gears a few times , put it in "P" , turn off engine - then do the drain & fill ... Repeat as required.
 
After I drop the pan and have removed the filter, I let the fluid drain for a couple days. Last time I did a pan drop on my Ford 4R70W transmission, I got seven quarts out of it. No, I would never run a transmission while cycling the gear shift with the pan off.
 
Any basis for that statement? I often start the engine and put it through the gears after the pan is empty. Usually get another half quart out. It's not like running an engine without oil so there isn't any cushion between the bearings. I only run it 10 or 15 seconds so the coating of transmission fluid still on the parts prevents any damage.
It’s exactly like running an engine without oil. There are bearings, bushings, sliding parts, pump teeth, and other parts inside a very complex machine that need lubrication.

Running it without oil is a terrible idea.

Perhaps because you flip these cars, you don’t see the long-term damage, but running a transmission, that is designed to be continuously lubricated, without oil?

Never.
 
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Running it without oil is a terrible idea.

...

Yes it is!!!

Do not do this.

FWIW, Honda's advice is to do drain and fill raise the car on lift > start and shift P>R>N>D then accelerate so that it shifts through all forward gears and immediately drain and fill again, repeating 4 times.

A similar procedure should be effective though, without a lift it goes without saying that this is not an easy procedure to do safely...
 
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