I posted this in the model year, but probably should be here.

I put 9 quarts of Mercon LV in a 2004 F150 thinking it was Mercon V. (after replacing the OD solenoid clip) Looking for the best way to change out the fluid. From what I have found this year does not have a torque converter drain, so either need to drop the pan and fill multiple times or I have seen some pump it out with the engine running through the the trans cooler lines. This truck does have a separate transmission cooler so the lines would be easy to get to. I have also seen some say that there is a thermostat in the cooler but does not appear to be on the separate cooler.

Any thoughts on the best approach? Can you pump out the entire system via the trans oil pump? Can you pump it empty and then fill or will that cause damage? Or is 2 or 3 pan drops the best?

 

Have it towed to a shop with a transmission flush machine with at least double the capacity of the transmission.

 

I spoke to a shop I trust that recommends not to flush this age of trans. (turned away the business) It could cause damage, and from what I have read others agree.

 

I'd bet Dorman sells an OE style pan but with a drain plug. I had to dig a bit to find the part number for my trans but Oreilly had it in store next day. Dorman made a quality affordable part in this case. Makes the drain and fill method very easy.

 

Won't get all the fluid at once and the meantime the wrong fluid is still in there. Flushing is the only way to get it all out at once.

 

Well, then just leave the wrong fluid in it.

If you trust this shop, why are you asking us? And why are you doing your own work (wrong)?

There are only 2 options:
1) leave the wrong fluid in it & see how much damage it does.
2) flush it with the correct fluid & see how much damage it does.
YOU already did the damage by putting the wrong fluid in. Which option do you think will do LESS damage?

 

The shop told me to drop the pan and change out the fluid a couple of times. He said that a diluted amount of LV in the system would be OK. I am just trying to determine the easiest way to accomplish this as dropping the pan multiple times will be a pain and messy. If pumping it out the cooler line works, it sounds like a simpler approach. I have found some info that there is a thermostat in the cooling system. So wonder were that is located, in the tranny or in the cooler. If in the tranny then pumping it out may not work since idling in the driveway will probably not get the tranny hot enough.

 

Drop the pan only once. Before you do it, buy a replacement pan that has a drain plug in it. Drop the pan, install the new pan. Refill with proper fluid. Drive around town for a day. Open the drain, refill. Drive around town the next day. Open the drain, refill. Do the drain/refill X number of times until you have your own feel-good feeling about it. Nothing else or more that anyone here can tell you.

 

^^^ THIS!

I bought a replacement transmission pan with a drain plug for my '05 but we sold the truck before I could install it. I believe the '04 and '05 used the same pan, but you can confirm yourself if you like. The pan is the "Dorman 265-813 Transmission Pan with Drain Plug." I think I paid $23 or something like that.


If you decide to go this route, PM me and I can give you a deal on the pan and plug. They're just sitting in my garage taking up space...

 

Other options are:
- a long small hose and a drill pump. Feed the hose down the dipstick tube. Use the pump to suck out the fluid then refill. Do this x number of times. Same as the pan drop.
- disconnect the cooler return line and put on a hose to direct into a bucket. Start truck, while transmission pumps itself out. When see bubbles or slow flow, shut ruck off and refill. Do this 3 times. This is effectively a full flush/purge of all the fluid.