AT flush machines

[Donald]

I am trying to better understand and/or explain the recent very poor UOA I got back from what should have been Amsoil ATF. You can read the post in the Transmission UOA forum.

So the shop that did the flush says their machine automatically pushes new flid through the AT until there is about 1 QT of new fluid left in the new fluid container. When they do the next flush, they just add more ATF (based upon next car requirements) and do not really worry about the 1QT of fluid remaining in the container. In my case, they would have added Amsoil ATF to the new fluid container and it mixed with this 1 QT of some type of ATF.

So my question is do most AT flush machines work like this and do most shops not worry about the 1 QT of fluid remaining.

 

[Al]

I won't recommend a flush. I have heard to many legitimate horror stories.

 

[Mike_Murrell]

I'm with Al on this one.

A local independent shop owner does a car repair talk show on local AM radio on Saturday mornings. He runs a fairly sophisticated operation; not some shade-tree setup. In one of his broadcasts a few years ago, he discussed this and after having to shell out for 2 new high $$$ transmissions that were done in by this process, he did away with the automated machine type flush.

I believe the pressure exerted has a tendency to break things loose and all it takes is a tiny spec of something to deep-six the box.

It "might" work if you first drained what you could, clean the pans and change filter, but even then, there could easily be debris in the system that could plug up a vital passageway.

I own a number of cars to include a '95 Rodeo equipped with GMs 4L30 transmission. The system holds 9.1 qts. I drain both the main and adapter pans for a total of 7 qts. + clean pans and change filter.

225,000 miles later the transmission is as quite and smooth as it ever was.

 

[ConfederateTyrant]

Donald,
The flush machine, at least the more common ones used today, use the transmissions own pressure in order to "force" (for lack of a better term) new fluid through the transmission. As old fluid comes out at a certain rate, this pushes new fluid in at the same rate. A lot of them hold up to 15 quarts, and the shops will flush 15 quarts through the system using this machine.

I personally prefer the manual flush, which is drop the pan, clean the magnets, replace the filter (if applicable), put everything back together, overfill by 2-3 quarts, remove the return line from the cooler, and pump out 2-3 quarts at a time until the appropriate amount of ATF is flushed through the system. This way, you will know what was truly done, and no need to rely on an unnecessary device.

I prefer to do a full thorough flush with Amsoil ATF, then a drain and fill every 30,000 miles, sample for a used oil analysis as well. No need to ever flush again, in my opinion.

 

[ARB1977]

Drain and fill every 30K with Amsoil Universal ATF and youll be good to go.

 

[Big Jim]

As a service manager in various dealerships, I have seen hundreds if not thousands of transmissions flushed without any drama at all, even on high mileage cars with putrid fluid.

 

[Terry]

I recently took advantage of our local Mitsubishi dealer's offer to B&G machine flush and refill my 06 Outlander as a little test of sorts. $149.99

I monitored the procedure in the bay from about 2 feet away as a Rico our fine young tech poured B&G QuickClean ( 11 oz.) into the old fluid and idled for 20 minutes or so. NOTE : The service manager and tech were shocked when I asked for a sample to be drawn BEFORE the 25,000 mile SPIII was added to or drained.

I was promptly assured any warranty issues would be covered even though Mitsubishi does not "recommend" using additives. Yes Terry Dyson is testing B&G additives! Transmission mind you....

The flush was done very professionally using 13 qts of fresh SPIII with 1 bottle ( 11 oz.) of B&G ATC + additive. I made sure fresh SPIII was loaded before beginning the procedure.

I know undummy.....

Promptly headed out on a 2000 mile highway trip with wonderfully smooth shift and best MPG recorded at 30.5 MPG @ 72 MPH on one tank. Average MPG up 2%.

Seems USPS lost the initial oil analysis and once it is found I will post here.

Follow up analysis will be posted too.

IR case temps recorded at 135F off highway speeds, at that temp I doubt any fluid will wear out too quickly.

OEM factory fill was visibly darkening from oxidation and shift was becoming much more aggressive, especially on down shift slowing.

Will keep all apprised of results of long term test.

Was impressed with veggie fluid oils ( soy based ) B&G is using in the QuickClean.

Sure beats my old 100% changeout technique slopping fluid all over the place.

Bottom line is sure you can service our test vehicle, while I stand right next to you and watch. Made Rico visibly nervous so I assured him I had turned wrenches for years and that the whole procedure would be shared here!

Terry

 

[Steelers]

Thanks for sharing your experience Terry. Years ago I had a fluid exchange done for $60 at a tire store. Not entirely trusting tire busters to service a transmission I watched the guy from start to finish. He used 12 quarts of Castrol Mercon V, it was a Ranger, and the T-Tech machine took about 45 minutes to completely change out the fluid. A good experience and a great bargain for the money. The dealer will almost always use the correct fluid but these other places you have to question and watch. Don't let them put generic Dex III and an additive. Use a brand and type of fluid that meets the car's specs.

 

[Donald]

The dealer will also not need to (in most cases) switch from fluid to fluid depending upon what car gets the next flush as an independent garage would need to.

What is needed is a place with a dedicated flush machine filled with Amsoil ATF.

 

[Tempest]

Quote:

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the T-Tech machine took about 45 minutes to completely change out the fluid.

---

Am I missing something here? I just did a cooler line trans flush this weekend and it took about a minute and a half to pump out the old fluid and add the new.

Terry, looking forward to your SPIII used oil analysis. The VOA on this fluid did not appear impressive. Of course not all is shown in a VOA.

I was going to get a used oil analysis of my Dad's Hyundai trans but he had the transmission fluid changed without letting me know first...

Does the BG cleaner stay in the trans?

 

[Lonnie]

Do you think that not every mechanic would be as careful as Rico was with Terry watching. In the TV clip here in the LA area the quicky lube guy did such a good job with the transmission flush that no fluid even touched the machine. That's being careful. I think that if you're interested in maintenance of your own vehicle enough to hang around BITOG and want to be really careful about your automatic transmission and are willing to spend the time and money you could just do a partial drain and top off every 15 to 30k miles. You could even use a synthetic replacement fluid. I'm doing 15k cycles on two cars and I would do something more if I though it would be any better, even if it cost more. I just don't trust a mechanic to do a good job with an a/t flush, sorry.

 

[ewetho]

Our BG machine hold 16 Qts so that is our flush. Most use MerconV so not a big deal for us. BG stuff seems to work great. Did my Fiances Focus at 127K when I bought it and 6K later it is running like a top and fluid looks good. I don't think it had ever been done although the engine was done religiously so it seems due to the level of deposits on the valve train NONE it was still silver in color!!!

They did a demo when we got our machines where they added acid to the Mercon to show it oxidized and black and then added a little of their additive at that gets added in the end and it turned it back to red fluid!!! No joke! We got the stuff out of our jug of oil and they put some acid on some metal to prove it was acid. Then in the end it was Red Transmission fluid again.

 

[Winston]

Terry,

How many miles were on your Outlander?

 

[MonumentOiler]

Some of the machines are little more than automated lube pumps. They stick the pickup/refill tube down the fill pipe and then the machine sucks out the old fluid, senses when it's done and fills with a like amount of new fluid. Nothing is circulated through the transmission and you could do better with a drain and fill since at least gravity is helping remove contaminants that way.

A good machine should attach to the transmission lines.

 

[HighTide]

I agree! most are machines are quick fluid exchanges as flat
rate mechanics will not be happy waiting for a tool. Had a
salesmen at our shop last September showing a demo. it could do any fluid. Coolant, trans, brakes and least of all motor oil... she diced and sliced....lol And Bleave me, I have seen trans flush machines at shops.. their expensive and and shops hold on to then forever. With the looks of them I would never hook my car up to one that must have all kinds of sh*t still in it from countless of abused and gas-n-go yoohoos... trying to save a trans thats already toast!