New fluid %

[disturban]

Math question...I have an 11qt system, I did a pan drop and refill and it only took 4 qts, I drove for a few weeks and drained the pan again VIA new drain plug and refilled with 4 more qts. How much new fluid do I have in there now? I realize I lose some of my new fluid every time I do this but I cant do a line flush because the lines are totally inaccessible unless I take a bunch of things out of the way. According to my figures I would say with my 2 pan drains and 4qt refills I should have about 58% new fluid...what if I did it a few more times? How many times would I have to do this to have 80% new fluid? I am trying to figure out how many times to do this before it is not beneficial, I don't want to drain 3 3/4 qts new and 1/4qt old just to fill back up with 4 new qts if that makes any sense? At the same time though I want to get as much of the old out as I can before summer!

 

[Colt45ws]

I was able to acquire the Fluid change spreadsheet off the wayback machine and I am rehosting on my server, for your perusal.
According to this, you have 60% new fluid after two changes. 3rd change will get you 74% and 4th change will get you 84%. Starts diminishing really fast after that. 90% -> 93% -> 96% -> 97%..
http://colt45.ws/misc/uoa/Tranny4Bobistheoilguy.xls

 

[disturban]

Thanks, that is exactly the info I needed...I think I will do it 2 more times and call it good for a year or so. I just wanted to get as much of the old fluid with 100,000 miles on it as I possibly could.

 

[mechtech2]

There are diminishing returns when you flush this way.
I am just noting this, not condemning it!

with an 11 qt system and 4 qt removals: [approx]

1: 36%
2: 60%
3: 72%
4: 82%

 

[Donald]

Originally Posted By: mechtech2
There are diminishing returns when you flush this way.
I am just noting this, not condemning it!

with an 11 qt system and 4 qt removals: [approx]

1: 36%
2: 60%
3: 72%
4: 82%


I agree, and its not green at all.

I know you said its a hassle, but on a one time basis, get some ATF hose, install a Magnefine filter in an easy to get to place, and do cooler line flushes via the output of the Magnefine.

I had a transmission shop install one (I gave it to them) for free in my Jeep. Of course I paid them over $500 to replace a pressure regulator and sensor (something like that) inside the transmission (needed a pan drop) so I guess they could afford to spend 5 extra minutes to install the Magnefine.

Just my $0.02.

 

[caravanmike]

Originally Posted By: Donald
Originally Posted By: mechtech2
There are diminishing returns when you flush this way.
I am just noting this, not condemning it!

with an 11 qt system and 4 qt removals: [approx]

1: 36%
2: 60%
3: 72%
4: 82%


I agree, and its not green at all.



my drain and fills are very green. i recycle all of my old fluid!! remember their is nothing more green than maintaining a vehicle. by maintaining my vehicle i am reducing the need for new manufactured goods.