Get 2 buckets, fill one with like 7gt of fluid. Set them side by side in front of the truck. Find the coolant lines running to your radiator. Figure out which line is pumping fluid and which one is returning it (Which ever line enters the radiator at the highest point is likely the one pumping the fluid). Unclamp the rubber hose from the metal hose and add you one 5/16 vacuum line to both metal hoses. Run the pumping line into the empty bucket and the returning line to the bucket filled with new fluid. Put the key in the switch and turn to the on position, the fluid pump should turn on without having to start the engine. Run it like this until you start to see new clear fluid coming from the old fluid line. Re-install the hose and then double check the dip stick. Make sure you have a decent amount in before you ever drive, coming up to at least the bottom of the dip stick. Then go drive for 2-3 miles and when you return run the trans through all gears (1...2...d...r...n...p). Leave it running and make sure the fluid level is up into the cross hatched area on the dip stick.

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2001 Ranger Edge
3.0 V6
Automatic
4.10 gears
97,780 mi