My car just hit 50k miles so I decided to swap it out this last weekend using the less common cooler line drain method. This is pretty easy to do at least on this specific Fusion, so I figured if anyone else was looking at how to do it, I would post my process.
Although a lot of people prefer OEM, for my new fluid, I'm using AMSOil's Multi-Vehicle Synthetic ATF. I was reading online and the reviews are very good, with most people mentioning that it highly improves their shift smoothness which I was interested in. After the change I can confirm that the transmission does shift a little smoother which is welcome.
My car in question has about 50k hard city miles, so following carfax's 'Severe' conditions guide, I decided this would be the interval I'll change it at. Plus, considering that the AWF21 is a 'sealed' designed with no pan and no access to the filter, it sets my mind at ease to do it this soon too.
This guide is specifically designated towards Fusion's, or possibly other Ford's, with the Aisin AWF21 transmission which requires fluid that follows the JWS 3309 specification. Just make sure you get the correct fluid if you're doing this on a car with a different transmission.
While looking for the cooler lines for the trans, I discovered that my car has a block heater installed, which I could have utilized a couple times this winter. So the more you know.
As mentioned, I am going to be using the less common method of letting the trans drain itself via a disconnected cooler line. The line that seems to work best is located directly below the air box on the drivers side of the vehicle. This is the cooler send line and is about the best option for this process.
To capture our old fluid, I used a section of 1/2" clear tubing that you can pickup at almost any hardware store. Just make sure that when you're attaching it, you CLAMP IT SECURELY! I originally had a standard band-style hose clamp that was just barely too big. I thought it would work, but it blew the line off after starting the vehicle, and I made a bit of a mess everywhere. After finishing my change, I took it straight to the car wash to spray down the engine bay, since ATF is flammable.
I ran the line directly down to the ground and out to a 5-gallon bucket. This method of fluid change means that the transmission will drain itself almost entirely, instead of leaving residual fluids inside of the valve body and torque converter. This allows for a more complete fluid change instead of just draining it. The torque converter itself can hold around a quart of fluid which wouldn't get drained in a simple plug drain and refill.
After ensuring the drain line is in place, just start the car and let the transmission pump do the work. Obviously the thought of running it dry sounds bad, but as long as you don't put the vehicle into gear, or run it for too long after empty, there is no risk of damage. Some vehicles don't engage the pump unless the transmission in is gear, but the fusion doesn't require this. If this is the case, typically putting it in neutral will engage the pump.
After draining the transmission via the pump, I still opened the drain bolt and got about another half a quart that was sitting below the sump. My transmission was a little low on fluid to begin with, but overall
I was able to get about 5 quarts out of it. This isn't the entire 7.4 quarts that the system holds, but it's as much as you'll be able to get without doing a full flush, which manufacturers have expressed can be dangerous. The fluid honestly doesn't look that bad, the camera makes it look darker, but it was still darker than the stock fluid so I still was content changing it.
After finishing up, I decided to use the injector-style of hose clamp that I used for my drain hose since it's much easier to work with, and it'll make it easier for the next time that I need to change the fluid. The OEM clamp is the 'elastic' style of clamp of which the teeth were completely downwards and it was a huge pain to get off. I kind of mangled it in the process which is why I wasn't confident on reusing it. I didn't even bother to take it off of the hose, maybe the next time around when I change it, I'll have a little more motivation and yank it off.
Refilling is pretty simple, I usually start with the 'replace what you take' method and put in around 5 quarts. That was still a little low so I added about another 1/4 quart, drove around the block a couple times, and checked and added until I got to the 'cool' level since the fluid was cold. Just repeat the process of add, check, add, check, until you get to the proper level. Make sure you're not making the rookie mistake of checking it with the engine off, transmission fluid levels are checked with the engine on, and preferably while warm. Unless you have a fill tube, which most DIY'ers don't, you can just add the fluid with a long funnel via the dipstick tube. It's a little slow, but works just the same.
For the next couple days I'll keep checking it and top it off if it needs is, also making sure the line I removed isn't leaking.
Thanks for reading!
Edited by BlueKoda, 17 March 2017 - 08:31 PM.