Simple procedure for Transmission Flush

[unDummy]

If you drain the pan 1st, you end up with a more complete flush.

Hoses/clamps should have no problem being reused.

I prefer the KISS method. Use a fluid extractor through the dipstick is easy and not messy. Drain/refill if you have a drain plug. Line disconnect if you have no other choice or want to remove most of the old ATF.
No need to make it more difficult then it needs to be.

 

[Donald]

If your vehicle has a drain plug then why not take the extra time to drain the pan before the flush since then there will be almost no mixing of old and new ATF during the flush. If you don't drain the pan first then you should use a few more QTs for the flush than the system holds. If the ATF is synthetic then you are spending an extra say $25 on ATF.

 

[MK2]

Originally Posted By: Gary Allan
Originally Posted By: Loopie
What will happen if your use the supply/send line instead of the return line???

Thanks



You'll get fluid out of the unexpected location (assuming we're still talking about flush procedures) ..depending on where you disconnect it. I'll figure that you're disconnecting it at the rad in either case ..so that's the liability. You just say "oops" and remove the other line. If that's inconvenient, you have a short piece of hose laying around just for such events and put it on the bare nipple on the rad...and proceed..


Yeah, let's say disconnecting the send line before the radiator instead of line after the radiator, because on my 4runner the hose clamp on the send line is easier to remove the the return line.

Do we need to use the return line to get rid of the old fluid inside the cooler/radiator?

 

[AzFireGuy79]

Builtwell, I have yet to install a bypass for engine oil although I have tossed the idea around quite a bit. The thing that has kept me from going this route is mainly the fact that I am running RL oil and my ideal OCI according to UOA is about 8K. I have had good luck with the EaO's thus far and figure they are much more economical for my given use.

Some people dont see the need for bypass filters in anything auto/light truck. Many will claim you can accmplish the same end result by flushing the transmission. While I agree that transmission flushes extend a transmissions useful life, I disagree that you are accomplishing the same result with a bypass filter. With a bypass the ATF is always clean. With a flush, debris build up in the course of lets say 30-60K. This is creating heat and wear. This is where a bypass really shines. It keeps the fluid clean and thus extends your OCI's and useful life. Of course I am telling you things you probably already know.

 

[Gary Allan]

Originally Posted By: crinkles
what i am worried about in disconnecting the trans cooler lines, is re-joining the pipes - are those clamps re-usable? do you need new ones? if using the cooler line flush method, why drain the pan in the first instance?


I'll assume you have hoses since you mentioned clamps. Some newer setups have hard piping and assembly line fasteners that I haven't figured out yet, but some auto parts store should have the low down on them. Ford is our queen of streamlined assembly ..and more troublesome after market service on some assemblies.

The reason some like to do the pan first is that they then know they've remove all excess debris from the collection point. When they decide to do it in a year or two, they then know how much they've shed in new material in their usage over the time/mileage span. Once they get a grip on it, they can skip the pan drop and just flush. This is particularly true if they've added auxiliary filtration.

 

[Built_Well]

Originally Posted By: Gary Allan
Some newer setups have hard piping and assembly line fasteners that I haven't figured out yet, but some auto parts store should have the low down on them.


The '06 Camry has a combination of hard piping (thin metal piping) and rubber-like hoses. For example, the ATF oil cooler's outlet hose is a hose that clamps onto a thin metal pipe, and it's the metal pipe that then travels to the inlet of the transmission.

The hose clamps onto the pipe vertically, so that the hose is pointing upwards at the point where it clamps onto the pipe. I assume this is the transmission's inlet pipe as the inlet point is located higher up on the transmission than the transmission's outlet point.

The outlet is also a thin metal pipe that connects to a rubbery hose, and the flexible hose travels to the ATF oil cooler.

The ATF cooler's outlet hose is closer to the passenger side of the vehicle than the ATF cooler's inlet hose.

 

[Gary Allan]

Sounds like a traditional setup ..devoid of contemporary domestic "pace of assembly" fasteners. There's a reason why the oil coolers on a Crown Vic has O rings and one bolt holding the hoses in place.

I was checking out a customer's Lumina ..actually, I check out every car if I have the chance ..but that one had oddball assembly line fasteners/clasps that I knew had some mojo learning curve to them.

 

[Built_Well]

Originally Posted By: Gary Allan
Sounds like a traditional setup ..devoid of contemporary domestic "pace of assembly" fasteners. There's a reason why the oil coolers on a Crown Vic has O rings and one bolt holding the hoses in place.

Oh good...sounds like I have the easier, traditional setup then.

I suppose you may have been describing something like the spring-lock coupling/connector and O-ring that metal fuel and A/C lines use. The "Popular Mechanics Complete Car Care Manual" says they need a special inexpensive tool to open them (Page 199). I love this book

But I recommend complete newbies to read "Auto Upkeep" first before jumping into the Popular Mechanics book. That's what I did.

 

[Jim Allen]

I'll inject a point.

I recently spoke with Ibrahim "Abe" Kahlil who, with John Eleftherakis, did all the ATF/filtration studies for those SAE papers mentioned in other posts. I asked him directly about cooler line flushes and he approved. BUT, he was adamant that it's vital to drop the pan and change the filter because his tests have shown that just a flush leaves a significant amount of contaminants in the pan (generally on the magnet if it has one) and in the filter. Dropping the pan and changing the filter is especially important on the first flush, because that's when the most contaminants are present. He said to avoid flushing machines that backflush, which should be avoided like the plague because they may (and he says often do) blow out the filter pad. He claims to have seen many transmissions that failed due to this.

His recommendation was to change the fluid and filter early on, and to add some sort of a filtration device. He is now working for a major filtration company and is part of a project working on improving internal trans filters. They will soon be offering a pan filter that's 40 micron nominal. Initial apps will be for new OE vehicles (the OE have glommed onto the fact that iron wear metals are the bane of electromanetic valves) but says they can retrofit the media to older applications. The best pan filters now with the MicroFelt media are around 80 microns, with the cheaper being 100-150. Many of the screens are 150-200 micron.

 

[Built_Well]

Jim, as always, your advice is top-notch and sound.

It would be nice to drop the pan, but it's also risky. I would probably end up with a leak after scraping off the old gasket, applying a new OEM Form In Place gasket, and applying sealant for each of the ATF pan's 18 bolts (the sealant must be applied and bolts torqued within a short time frame, like 10 minutes), or you gotta do it all over again--according to the Camry factory service manual.

I suspect even a transmission shop runs a good risk of causing a leak, as I read in one thread that somebody had to take their car back to a shop after the shop dropped the pan. So the shop re-did the work. The first time wasn't good enough.

Probably for some models and makes, a pan drop makes very good sense, but I think for the 2006 Toyota Camry, it probaby isn't necessary. AzFireGuy mentioned he found no debris (or just about no debris) in his pan when he removed it from his '06 Camry SE after 30,000 miles, IIRC.

Plus a former Toyota employee who is a Toyota expert with lots of official certifications told me I should nix the idea of a pan drop on the '06 Camry. Again, I'm just talking about my make and model. This may not apply to some other makes and models.

Lastly, I'll just say I used my hand to sift through my 4 quarts of drained ATF last week when I did a drain and fill of the T-IV, and my fingers felt absolutely no shavings at all, not even a hint of a small shaving. (I used one of those neat, large, green 5-gallon no-top draining pans from Blitz to catch the drained ATF.) I hope I didn't get cancer from wading my hand in that used ATF! {Lol} Used motor oil is suppose to cause cancer, and I believe it.

 

[Built_Well]

So both fellas in both tutorials above turned their car off after flushing out just one quart of ATF through the ATF cooler hose, then poured a quart into the ATF dipstick tube while the car was still off. Next they turned the car back on to flush out another quart, then turned the car off again to add another quart of ATF. And they repeated this procedure many times.

I guess they did this because one of them expressed concern that it might be bad if the ATF pump sucked in air instead of fluid. Is this a valid concern? If you don't turn the car off and just let all the ATF drain out the ATF cooler hose until no more fluid is left to drain out, can this hurt the transmission since the trans would be operating for a short time without ATF fluid, and the pump would be sucking in air?

 

[AzFireGuy79]

In most applications you can flush two quarts at a time without issue. I usually drain the pan, fill to factory specs and proceed to flush two quarts at a time. If you see cavitation(air in the flush hose) just shut down and refill. Either method is fine.

If the pump sucks a little bit of air it won't hurt anything, but you should never let it run completely dry.

 

[Gary Allan]

I wouldn't want prolonged cavitation ..but you're under no load and nothing much is spinning.

I believe Ford recommends doing the initial pan drain (via cooling line ..and then adding 10 quarts at once. pumping until the line cavitates ..refill/top off ..the end. I've only done the pan capacity (usually 2 quarts) cycle thing. If I had someone else with me, I'd have them start adding quarts on a continuous basis and stop when there were 3 left.

 

[crinkles]

what kind of pressure would the ATF be under when going thought the cooler line circuit?

 

[Gary Allan]

Mine at idle ..with a cooler downstream, will see 30-50psi. That's cold fluid ..but I think that it would just mean more fluid would be passing at higher pump speeds at lower visc. I've never reached my limits. It's usually a lower pressure regulated circuit. By lower pressure I mean that it won't see the 200lb+ pressures seen in the trans for something like reverse.

Some who have put Permacool sandwich adapters on remote full flow mounts so that they can add a MG or Frantz bypass have had to drill a small hole in the sandwich to stop the poppet relief and the pump relief from banging around. They "argue" between each other convulsively trying to regulate the flow due to pressure alterations that change greatly with very little flow change.

Naturally, YMMV since there are many variations of transmission, but that's what I've observed. The hoses can be rated at 150psi or 250psi (iirc) at higher temps than you'll probably encounter. I'm just uncertain what the pressure limits would be for an in rad cooler.

 

[Donald]

When I have done a cooler line flush, it did not come out very fast and did not squirt too far so I would be surprised if it was really 30-50psi. Given the cheesy spring clamps they used on my Camry from the factory, I'd be surprised if they expect much more than 10-15psi.

 

[Built_Well]

This is what the "Popular Mechanics Complete Car Care Manual" has to say about ATF flushing and the repeated "car-on" "car-off" method:

"Put the hose into the largest jug you can find, and let the engine idle until air starts spurting."

[Hmm, it seems the book's contributor doesn't think it's necessary to turn off the engine and add a quart or 2 quarts at a time. The writer seems to be saying to just let the engine idle until all the ATF is out and air starts spurting from the ATF cooler hose. But this method must not allow for the best lubrication of the transmission during the flush if you just let the engine idle until all the ATF is out.
I dunno, I think I'll stick to the on-off method of adding a quart or two at a time after turning off the engine, or do the following:]
[The book's next sentence is:]

"Many professionals enhance this procedure by pouring a few quarts of fresh fluid into the dipstick tube at roughly the same rate that the old fluid is coming out, thus adding flushing action."

The problem with the above may be that it might be hard to keep up with the faster outflow of ATF out the hose. A Google search turned up an account by someone who wrote that he wasn't able to keep up with the fast outflow of ATF from his oil cooler hose. So he'd turn his car off periodically. I guess each car is different. But again, the first sentence from the Popular Mechanics passage above implies it's not important to pour anything into the ATF dipstick hose until after all the ATF has drained out of the cooler hose and air is spurting.

So there you have it. Folks do it differently, I guess. That's 3 different ways to flush your ATF.

To summarize the 3 different methods:

1) Just let your car idle until all the ATF is out and air is spurting from the hose.

2) Let your car idle while, at the same time, adding ATF down the dipstick tube.

3) Turn your car off after every quart or two of ATF has drained out, and replace the lost quart or two with new ATF whle the car is off.

 

[Built_Well]

So pick your poison, I guess. AzFireGuy seems to prefer Method Number 3. UnDummy seems to prefer Method 1, if I remember what he wrote in a different thread. And Gary Allan seems to prefer Method 2. What's your favorite method...

 

[Donald]

Method 2 would seem to be the best (after the pan is drained) but with some cars you cannot get the new ATF down the dipstick fast enough so someone else need to be watching the drain hose for bubbles and reporting how many quarts have come out so far.

 

[Gary Allan]

Originally Posted By: Donald
When I have done a cooler line flush, it did not come out very fast and did not squirt too far so I would be surprised if it was really 30-50psi. Given the cheesy spring clamps they used on my Camry from the factory, I'd be surprised if they expect much more than 10-15psi.


I think you're correct. If you reread my post I told you that was an "in line" reading with the whole circuit hooked up through the cooler (actually TWO) and about 8' of extra tubing for the filter. Draining out an open hose probably is your alleged 10-15psi at the trans ..depending on how long the line is to:from.

..and clamps are just fine up to the rated hose pressures. Even the weatherhead without clamps can take high pressures.