How good is a Trans flush thru the dipstick?

[Donald]

My guess is that 0% of the quick oil change places will do a drain and refill of the pan (even if you request). If you go to your favorite shop, while they may not offer it but they should do it if you request (and pay extra).

The flush machine is a money maker for them, and in most cases its easier to just flush with +2 extra quarts of ATF than drain and refill the pan first.

Not saying +2 extra quarts is as good as a drain and refill of the pan first, but its getting closer.

However as I have pointed out before if the cost of the ATF per QT is expensive (synthetic) then one needs to do the most efficient flush using the least amount of ATF to get over 90%.

 

[ZZman]

That machine will do a fill thru the dipstick as it sucks out fluid thru the cooler line. They just chose to do it the faster and easier way. I will know better next time.

 

[Donald]

Hey thats we are on this forum, to learn and share experiences.

 

[Big Jim]

Originally Posted By: CrAlt
Originally Posted By: Big Jim
And today, just how many transmissions can you drain the torque converter on?

I really have no idea. And since you say that im guessing only the higher end cars? All mine have it. And all after market ones that reuse the 11" OEM cores seem to still have it.

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but they don't so we need to figure out the best way to exchange fluid for the particular application.

I Agree. But it sounds like there is only 2 systems. How can they be the best for all applications? Im sure chryslers are not alone on how they cool the fluid. The return line from the cooler goes STRAIT in to the sump. No different then dumping it down the dipstick tube.


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In my mind, the cooler line flush is the premium answer for most cars. You flush until the fluid coming out is as pristine as the fluid going in. Usually the published capacity will do that although you often need a quart or two more if you started with a really dirty system. Extreme cases may take a little more.


I just dont see how you could get any ware near 90% new by just swapping in the same capacity. Your limited to what the transmission pickup can reach. You have way to much old fluid stuck in there thats getting mixed in. And I don't think "looks" is a very scientific way of judging the quality of the job.

Maybe if they had a system that sucked the pan dry via the dipstick THEN ran the exchange via the cooler line? Maybe then you could get in to the 90%'s...

The number of cars on the road today that you can drain the torque converter on are so close to zero that you can write off the rare few that do as an aberration.

I have performed many trans services from the hose in a bucket method and observed hundreds more. If you doubt its efficacy, I suggest you try it.