DIY: Full Flush for Automatic Transmission

Hey Erik, how long have had the Mobil 1 Syn ATF in your truck? What do you think of it?

 

It's been covered in here. The machine at dealerships and other shops has its own pump. The home equivalent would be using 2 seperate containers. The fluid is only pumped out and NOT sucked back in.
If you could come up with a container that used the pumped out fluid level to push new fluid in we would love to see it!

 

The return line from the cooler back to the trans just dumps fluid into the body/pan of the trans, doesn't it? There's no suction there - the suction is down in the pan - through the filter.

So that flush machine you mention would have to have a matching flow rate pump to install the new fluid. How could I easily arrange that in my driveway?

PHM
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You could stick a big funnel onto that hose and time how long it took a quart of ATF to run in via the return hose. And then so long as it's less time that the ATF is taking to pump Out - all would be well.

By myself I think it would be too much to do all at the same time. Once the outlet hose showed bubbles - so I apparently ran the trans pan empty of fluid.

Also; I don't why overfilling the trans pan while doing this DIY flushing would matter either. The engine only idling and say ten quarts of fluid in the pan instead of the standard four - in 30 seconds it would all be pumped out of the pan anyway.

I might do it again - although another 100K miles seems Way down the road to me. <g> But my alternative idea is:

I change the Mobil 1 every 15K miles (I used to change it at 10K but I'm not doing that any more) - so how about if I drain the ATF at the same time? Refill with the three or four quarts drained out and so essentially 'change the ATF' every 60K miles.

PHM
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You will get some naysayers that adding clean fliud to dirty is not intelligent. But, the reality is that tranny fluid is not under the same stresses as engine oil. Engine oil is subject to exposure to the burning of hydrocarbons, which makes contamination of the oil over time a fact. Burning hydrocarbons is just a dirty process.

The tranny, on the other hand, is not subject to this exposure, but is used as hydraulic fluid and lube for the clutches. Oil itself doesn't deteriorate too badly by itself, but the additive package does. Adding a pan drain's worth of new fluid to the exisiting replenishes the additive package and restores some of the viscosity breakdown that will still occur due to shearing of the hydrocarbon chains in the clutches. So, my opinion, from the research I've done, is periodic pan drains of the tranny are just fine.

My truck is on a 25K pan drain interval. About to get the 50K one done in the next couple of months.

 

Any amt. of clean transmission fluid mixed in with dirty fluid is better than just dirty fluid.

Don't know about the newer ones, but 4 cyl Accords from the 80s held 6 qts. - you drained only 3. There was no easy diy method to get the other 3 out. I would drain tranny fluid every other oil change and refill with 3 qts. Car had 375,000 miles on it when sold. Same tranny.

Have done the same with my wifes '06 Avalon. Holds about 7 qts. - Drains 3.7qts. I do this every 25K - WS fluid. Car is pushing 200,000 miles and shifts beautifully. Pan has never been off; fluid has never been flushed.

For my Tacoma - I will follow the flush method here, but will first see what drains in that unit at 25,000 miles and maybe, depending on how much is drained the 1st time, refill with that amt. - followed by a drive and one more drain/refill. Depending on how much I am able to drain from pan, I may do the drain and fill at 25,000 mile intervals and the flush at 100,000 miles along with a filter change/pan&magnet cleaning.

If you are only doing pan drains, something that might help get a little extra out is to elevate the front of the truck with a floor jack as high as it will go. This approach drained an extra 1/2 qt. from the trannies in 2.4 & 2.7 liter automatics - 1st gen. I'll find out if it also applies here the first time I do a pan drain.

This approach has yet to fail me in the 30 yrs. I've been using it.

 

Very nice man, At this point one should ask himself? it is a lot of work, how much will be to have it done by professionals?
This for older folks like me.

 

Max 200 bucks

 

I just did mine and it ran me ~$130 for fluid, new washers, and a $20 chemical sprayer that I used as my fluid pump (which worked awesome BTW). I drained/filled from right at the tranny cooler which is really easy if you pop the grille out.

Toyota quoted me $260.

 

So how did all that work?

 

The chemical sprayer or doing it from behind the grille?

 

chemical sprayer really, trying to envision and just not

 

This is the one I bought. I removed the nozzle and cut the tip so it would flow more steadily. Then I attached a small piece of the clear tubing to the end of the sprayer and stuck that onto the metal return line of the vehicle.

I had my buddy turn the truck on and off for me while I stood at the front pumping away. I couldnt keep up with the flow rate of the tranny pump so I'd have him stop at roughly 3L and let me catch up. I would think that if you removed the handle piece completely and just ran the straight tube to the vehicle you would be able to get much better flow but I was just happy to not have to get under the vehicle several times to fill.

Other then the location I did it from and the pump I used, it was the same proccess as the OP so kindly layed out. Hope that makes sense.

Cheers!

 

This seems like a great idea! How long of a process would you estimate this took you?

 

Had I been organized, and not extremely hung over I probably could have done the flush part in roughly 30 mins. Then the fluid level check is the big variable. I let it get too warm so I had to take a lunch break lol.

 

I like the sound of it and it would play well at a corporate meeting. <g>

"Let's have a professional do it." it has a nice ring to it. <g>

But we're talking about having some fluid changed here. The profesional who will almost certainly do this job will be the newest helper-type guy who is being paid the least at the establishment you choose, and will be being screamed at all day long to work faster and cheaper.

And look; I not trying to trash-talk the fluid flusher guy - that is not my point. I'm just pointing out that his priorities are almost certainly in at least some contrast to yours, and they could easily be diametrically opposed. <g>

PHM
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Great post, thank you for the time and effort put in.

 

It's possible he could be one of the more seasoned techs, but no matter. This is likely a flat-rate pay job(like most are these days) and the sooner he checks off on it the sooner get gets to start another.

Use this thread and the one by Fortech and do this job yourself. It ain't that hard and in the end you will know it was done by the one and only person on the planet who gives a phuck about your Tacoma.

 

Subd

 

Excellent writeup except for one quibble.
I see here and several other trannie threads saying replacing the crush washer is optional.
I must disagree with not replacing the crush washers while spending time and money to flush.
Simply not sound practice.

By definition, crush washers are one time use.
It is what seals and prevents seepage.
A new crush washer and a torque wrench is the best defense against stripping the plugs while ensuring the plug is tight.