Artbuc

Good Morning! I am brand new to this forum and to Hondas. Our 2010 MDX is the first non-Toyota vehicle in 37 years. I do all maintenance and repair work on my cars so I am beginning to think about the MDX. I am anal about my cars and already made my first mistake on the MDX - drained the FF at 5k because I couldn't stand to wait for the MM to give me the go ahead.

On my Toyotas, I always did multiple drain/fills for ATF but recently became aware of the manual flush where you collect old ATF from the cooler return line. Apparently this is a widely used practice.

It appears that this method is NOT recommened for Hondas. Everyone seems to STRONGLY recommend the 3X drain/fill approach.

What is it about Honda transmissions that makes the DIY cooler return line flush so bad? Seems like this approach replaces ATF (especially in the TC) more efficiently.

Thanks.

C25A1guy

It really has to do with the seals and the valves on the Honda ATs. Even on my Rideline I do a 3x drain and fill, but I do space them out. This next time I do my oil change, it will be my third time for essentially a full change over to the new Honda ATF-DW1. It's generally a bad idea to run the transmission dry while it's running.

larso1

I have done the fluid drain from the trans cooler return line on our previous vehicle which was a Dodge G. Caravan. It was in accordance with the procedure in a Mechanics Illustrated article. It's supposed to be one of the few ways to evacuate all the fluid, including the torque converter. Start the car, put in drive, then reverse, then neutral, then cycle through again. Leave engine and emerg. brake on and drain. Seemed to work fine and no problems with the tranny. But I wouldn't do it with the MDX just because Acura is so explicit about doing the 3x drain and fill method. Supposedly the power flush method available at service places can dislodge debris accumulation in the tranny and cause more problems than it's worth. One really annoying thing is that Acura keeps changing the recommended trans and rear diff. fluid for the latest gen MDX. My '08 owners manual specifies ATFZ-1 for both. Then, it apparently was no longer available and then DW-1 was the approved replacement for both. Now I understand DPSF all wheel drive fluid is recommended in the rear diff. only.

SAKozicki

I agree and have done this method on several Honda and Acura vehicles I own. I think there some confusion between the "flush" as in the You Tube Video "Ten Minute Transmission Drain and Flush," which, by the way, was done on an Accord in the video, and a "Power Flush" done at a transmission place. You and I do the the "Ten Minute" method, which I think Acura has no opinion about. I thinks it works great and saves a couple of quarts of that tranny fluid which costs more than gold. I also use a combination of Redline D4 and F1 synthetic fluid, which really cuts the wear on the clutches. There is no goop on the drain plug magnet when I drain. I have so much positive experience with this method on so many cars that I can state, from my own experience, that there is nothing wrong with the "Ten Minute" drain and flush method. Kudos to that British "bloke" for making it. I will add that I am able to do this method on a 2000 TL which does not have a tranny cooler, but does have similar fluid return lines which work the same. Go and "flush" with confidence my friend.

Artbuc

We are in 100% agreement. I have researched this topic extensively and have found, universally, that people totally confuse the "Ten Minute" plan with machine power flushes that can backflush, under pressure, contaminated ATF into valve bodies and other critical components. Intercepting old ATF before it dumps back into the pan is NO different than draining it out of a plug. The only problem would be if someone ran the pump dry, especially for an extended period. Also, I'm not sure if this pump would have any problem self-priming. I don't think so because it is a positive displacement type pump but I am not 100% sure.

larso1

I think you are basically running the pump "dry" with this method, otherwise you wouldn't know if you got it all or left a few pints in. But it's not under pressure because you're in neutral and there is always enough residual oil in the pump to keep it well lubricated for a short period of time, after it's all drained out, before damaging it. I'm pretty sure it also has a flooded suction so priming problems should not be a factor, especially in a PD design. But, I'm not a transmission expert and I wouldn't stake my life (or my transmission's health) on anything I just said.