To Flush or not, debate over yet?

[shelbydog25]

I'm leaning hard towards using Mark Kovalsky's "flush" technique in replacing fresh ATF in my 4R70W by disconnecting the return cooler line and pumping the old ATF into a nearby bucket... But I've also seen posts (and had a AAMCO tranny tech, alledgely knowelable of Ford tranny's) warn me Fords and Chryslers are NOT to be "flushed" since loose particles could bugger up the valve body. Seems to me, if I'm just running the engine and the flow of ATF is following it's normal direction of flow, how would this push up loose particles, they'd already done so by now... Any comments? By the way, anyone who has "flushed" their 4R70W, both lines go into the tranny at the same spot, one above the other, which one is the return line ?

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[TexfordD]

do it at the radiator...disconnect the top line going to the radiator...attach a hose to it using a clamp and have the hose long enough to run to a bucket or a large catch can on the ground...clamp the hose to the inside edge of the can(bucket)..use a long neck tranny filler funnel and have lots of bottles of tranny fluid open and ready to go...I used 15 quarts last time I did it...have some one sit in the drivers seat to operate the key and shifter and have at it(don't forget to set the parking brake and chok the wheels)..have fun

[shelbydog25]

TexfordD,

thanks for the reply, but if I catch the old ATF as it's being pushed out before the radiator, and I pour in the new ATF simultaneously (directly to the pan), won't the new ATF be pushed back out , leaving the return cooler/lines and torque converter with old ATF?

[TexfordD]

no it goes thru all that before going to the radiator and when its returned it just spills out into the pan