How much trans fluid?

[BTR]

How many quarts of trans fluid do I need to flush the trans using the technique where the lines to/from the radiator are unhooked, fluid is drained while the engine is running, and new fluid is added through the dipstick hole?

2000 Explorer, 6 cyl, 4.0L, SOHC

 

[jlsparky7]

Probably 5 qts.

 

[66427]

I don't know how many, but a flush will take more than 5.
I'm thinking more like 15...

 

[waskly]

why would you want the trans to pump all the fluid out, and overheat doing it?

just do a partial flush, with they truck off, drop the pan, and new filter/gasket/ about 5 -7 quarts of fluid.

 

[SoNic67]

... using the technique where the lines to/from the radiator are unhooked, fluid is drained while the engine is running, and new fluid is added through the dipstick hole?

Nonono... the new fluid will be sucked by one of the lines and the old one will be pumped out thru the other line.
Nothing should go in the dipstick.

Bad part: by this method, you will need almost double the ammount of fluid in the system, to be perfectly "replaced". That is some 30 quarts!
Of course, you can do a partial flush.

I usually just do the pan and filter. I have also added (for a while) an external filter on the lines that go to auxiliary cooler (they are ruber hoses, easy to work with). Drove with that filter for some 500 miles, without forcing the transmission, and then pull it out.

 

[BTR]

Will it suck trans fluid into the other line?

Hmmmm. Will it actually suck trans fluid into the other line (the line that fluid is not coming out of)? I thought the other line wouldn't suck-in fluid because the fluid was "pushed" into the line by the outflow from the trans. Thus, new fluid had to be added via the dipstick hole. ???

 

[budwich]

I think you are right... at least according to some posts. Actually, there was discussion about "which line"... in that discussion, it was "indicated" that you will see fluid come out of BOTH lines.... :-( Basically, you need to "cap" one and have a receiver pan / hose on the other. The "plan" that was indicated was you run your vehicle for a "brief period" to get about 4 litres/quarts of fluid out, then stop, and then you add thru the dip, replacing the 4 liters. You do this "method" for a "period" until you "like" the color (fresh) coming out or until... your supply of replacement fluid has been depleted along with your wallet... probably in the 16-20 quarts/litres....