Can you do a Full Flush and a Pan Drop for the ATF at the same time? (Tow Package)

2014 Tacoma V6 with Tow Package

So I'm planning on doing the transmission pan drop and clean the magnets/pan/replace filter and thought to myself why not do a full flush too?

When I drop the pan I'm expecting to collect about 4 quarts of ATF since you get about 1 extra quart than when you drain via the plug alone.

The part about the full flush that I'm unsure of is the actual draining of the hoses and radiator. Our popular sticky thread says not to let more than 2.5 quarts pump out via the hose when you turn the vehicle on because the pump shouldnt run dry.

Since I have the tow package, I have the smaller envelope size Transmission Radiator. Am I even able to pump out 2.5 quarts of ATF from this little transmission cooler? Or should I expect less?

 

Could you put the pan back on, then fill it with the same amount that came out, then do the flush?
I’d suspect you’ll see a difference in fluid color once new fluid starts coming out the cooler hose.

 

I dropped the pan and filter, replaced, overfilled by about a quart, then popped the cold side of the transmission cooler (to make sure I was getting as much old ATF out as possible) and pumped another 3.5 quarts. Added an extra half quart to make sure I was high on the total fill then did the level check procedure.

IIRC I got almost exactly 5 quarts from the pan/filter. I used an old washer fluid bottle and marked it in half quart increments using water, measuring cup, and a marker to keep track of what came out.

8.5+ quarts of old out and new in is, IMO, perfectly sufficient. If you wanted to you could just do a drain/refill at your next couple oil changes to get the ratio even higher with little further effort.

 

Drain and drop the pan. Clean. Replace filter, put pan back on and refill.

Then proceed to go through the full flush process, noting that you already replaced 3-4 of the total ~11 quarts. (What ever you measure from the initial pan drain n drop)

The " only pump 2.5 out" means only pump that out before refilling the pan (you don't want to suck air). Do 2qts at a time (easier to measure it coming out and replacing). Until you have replaced 11 qts total then add in a 12th quart. Let truck and trans cool for a few hours then do temp check mode and drain excess via check plug.

 

Why not connect the pickup that’s inside the pan to a jug of fresh fluid and plumb the return to a bucket? Start the truck, run it through all the gears until you see fresh fluid getting pumped into the bucket. Then put the pan back on, top off with 4 or 5 quarts then do the temp check to get the level perfect.

 

Doesnt work like that. The fluid is pushed through the cooling lines and drops back into the pan. the pickup in the pan isnt something that you could easily plumb onto

Its a pretty easy process, unhook return line from ATF cooler put in marked jug. Make sure pan is topped off, turn on truck and run till 2 quarts is pumped out and turn off. Drain 2 quarts into holding jug, replace 2 quarts missing from pan with fresh, and do this till you have collected a total of 11 quarts. Adding the 12th quart at the end insures you only have to go through the temp check process once.

 

With that process you don’t drop the pan, clean the magnets or change the filter screen. You are also putting clean fluid into a pan with 2 quarts of dirty fluid.

 

This is the correct way to do it.

 

If you follow the process as described in the DIY you drain the pan completely (95% of the old fluid in the pan comes out without pulling the pan) and fill with new fluid before pumping, there will only ever be fresh fluid in the pan during the 2 quart pumping out sessions.

 

I have a flush machine that connects to the transmission filter sump . You remove the transmission pan and filter and connect the flush machine directly to the transmission pump inlet .
I save all kinds of money on fluid by flushing the transmission with the pan removed . Its messy because the fluid that normaly dumps back into the pan is now dropping to a catch tray . This is done with the engine running .

For you guys at home who properly drop the pan to perform a contamination inspection before you flush , its a good idea to add a couple quarts of fresh fluid to the clean pan before you start the engine , then flush the remaining fluid out . A flush mixes old fluid with new until you get that nice red color .

On another note if you have the time after your " clean pan" is reinstalled , you can disconnect the transmission cooling return line from the transmission and allow your torque converter and cooling system to gravity drain . Its going to take a long time for 8 quarts to drain out of the tiny cooling line but you will get the same results as a flush without using the transmission pump to force and mix the fluid out .