Before you folks said why. Well to make a long story short this is not on my Mercedes. It is on my BMW that does not even have a tranny funnel.

I ran across this on youtube. https://www.youtube.com/watch?v=MsdPAadc9fY

I want to do a drain and fill on my tranny. So my question do you folks see a problem with pumping tranny fluid in the tranny return coolant line to fill the tranny. This surely be a lot earlier and safer then to craw underneath a running car. The car has to be running to check and fill the transmission fluid level if you don't have a tranny dipstick.

I am particular interested in hearing from those of you who have experience or doing this is or similar procedure before.

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Silver Honda Accord, 2006
Silver G500, 2003
Silver SLK-320, 2002
Black ML-320, 2000
Bule Porsche 993 Targa , 1997
Silver Merkur XR4Ti, 1987

a few points to note when looking at such a problem.

1 - does the design have ATF coming to the cooler in the radiator or does the design have coolant going to the transmission to cool it down, (yes some designs like this exist and usually have a sandwich cooler on the unit)

2 - if you have ATF cooler lines then filling up the ATF from the cooler line is not possible unless you have a pressure motive to push it in (dipstick funnel motive is gravity - here your cooler line is usually horizontal.

3 - how did the factory fill it up? - there must be a filler plug and a checking plug or overflow tube or something like that. (service manual can tell you that)



the video you posted is a plain ATF to radiator system - one line is disconnected, dumped into a bucket, the transmission oil pump pushes it out, and then the unit is filled from the dipstick hole or in some honda situations a bolt plug on the upper side of the casing.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

1 - does the design have ATF coming to the cooler in the radiator or does the design have coolant going to the transmission to cool it down, (yes some designs like this exist and usually have a sandwich cooler on the unit)

2 - if you have ATF cooler lines then filling up the ATF from the cooler line is not possible unless you have a pressure motive to push it in (dipstick funnel motive is gravity - here your cooler line is usually horizontal.

3 - how did the factory fill it up? - there must be a filler plug and a checking plug or overflow tube or something like that. (service manual can tell you that)



the video you posted is a plain ATF to radiator system - one line is disconnected, dumped into a bucket, the transmission oil pump pushes it out, and then the unit is filled from the dipstick hole or in some honda situations a bolt plug on the upper side of the casing.[/QUOTE]


More info regarding you questions.

1. You are correct the ATF has to be circulated out and then return to the Tranny for this method to work. If the ATF is cooled by having coolant circulated into the tranny this method will not work.

2. I am thinking of pumping ATF into the ATF return line to fill the tranny. Like in the video the guy use compress air to blow what ever ATF fluid in the line back into the tranny. I am thinking of attaching a pump to pump ATF back in.

3. Yes there is a fill plug and check plug. However to fill and check the ATF level engine has to be running. Because the fluid level is higher when the engine is not running like all tranny. The correct level is to fill until overflow from the fill plug again you have to do while the engine is running. This is something I want to avoid because I don't want to be crawling under a hot running car and messing around with a pump.


So it goes back to can you pump ATF into the tranny via the ATF return line from the cooler. Is it safe to do. thanks

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Silver Honda Accord, 2006
Silver G500, 2003
Silver SLK-320, 2002
Black ML-320, 2000
Bule Porsche 993 Targa , 1997
Silver Merkur XR4Ti, 1987

you can attempt to do this - it wont be the prettiest job as fluid moves quite quick in those lines and you still have to measure the level from under the car anyway.

Two garden sprayers connected together can be a good flushing solution, one tank collects the old fluid while the other is simultaneously pushing new fluid in.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

As Zulf said, those lines can shoot ATF out in a hurry. At the end of the day you still need to check the ATF level from underneath.

If you really can't get under the car, I would recommend a shop. ATF change is so infrequent nowadays, you can take the one-time hit to your DIY ego and your wallet.

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Prost!

I am in the middle of replacing the A drum in my Jag (same transmission), so i am watching this post. All I have seen is the under the car method and like you, I am not looking forward to it.