Alright... I've been kicking around an idea for a while now. This probably won't work, but I'm going to toss it out there and see if any of you can support or disprove it.

I was thinking about a way to do a cheap mechanical fluid flush for the tranny. Essentially my idea was a box of new fluid being forced in to the transmission by old fluid being pumped out of the transmission and in to the box.

Here is how I see it working.

The two lines that lead in/out of the tranny that go to the tranny cooler. My understanding based on an explanation from Wes is that the force of that system is being "pushed" out of the tranny.

Of course, that is the part that makes this difficult. If it were simply "sucking" fluid in as the tranny was "pushing" fluid out then all we would need to do is set up an empty container to catch old fluid and a container of new fluid to get sucked in to the system. But, that's not how it works....or, at least I don't think that is how it works.

Since the new fluid is going to need to be pushed in to the tranny, it is important to make sure it is being pushed at the correct rate. And, in my opinion, the easiest way to make sure the right amount is going in is to let the amount coming out determine it.

I envision a single clear box (so I could monitor progress) with a 14 quart volume (14 quarts being the full capacity of the tranny). There would be two nozzles on the box, one at either end. Inside the box would be two clear plastic bags (of significant thickness), each attached and sealed to one of the nozzles. One of the bags would be filled with 14 quarts of new ATF while the other bag would be left empty. The "output" from the two tranny lines leading to the tranny cooler would be attached to the empty bag. The "intake" line would be attached to the full bag. After that, theoretically, the process is easy. Start the car, wait for the transmission to flush itself. The tranny would pump old fluid out and in to the empty bag. That would, of course, create pressure inside the box and force the new fluid from the full bag, out that nozzle, and back in to the tranny.

As I see it, there are a couple of potential stumbling blocks.

First. I am an idiot and have a difficult time believing that I might have thought of all the potential problems.

Second. I am not sure that fluid coming out of the tranny is under enough pressure that it could sustain itself against the pressure of 14 quarts of non-moving fluid. I see this as an issue with kinetic v potential energy. That full bag of fluid represents a significant amount of weight if taken as a whole. Would the tranny be able to push the fluid hard enough to start pushing fluid out the other side of the box?

Finally. Wes already said this was a stupid idea. So, I'm assuming he is correct. But, can't hurt to run it past some of the other experts.

Anyone want to weigh in on the viability of this system?

Dude, not stupid but consider this; it's not exactly pressure out, pressure in. The fluid is being picked up (sucked) from the pan, a reservoir, and pressurized in the pump and pushed through the transmission onto the cooler. Fluid from the cooler is dumped back into the pan.

All you have to worry about is keeping the pan full enough not to cause starvation. Which means you can either manually fill it (fast) or attach a fluid pump to pump in the new fluid. The fill rate and transmission pump rates won't match but you have some margin, don't starve the pump and you should be okay. Remember the trans is not under load parked and starvation (introducing air) of the pump is not that critical.

My opinion stands... It sounds like a $20 ticket to roasting a $2000 transmission... I would never attempt this on my Q. What was SO WRONG wiht the drain, run for 2 mins, refill and do that 3-4 times.... to get pretty close to a regular flush (say 90% vs 95%). Plus, you always change your tranny fluid WAY before it actually NEEDS changed (because its nasty/broken down).. it should always come out looking only slightly different than it went in....

ideally you could make your own flush machine by using a simple fluid pump with a regulator... You can assume that 4 quarts/min would be sufficient even if the pump pumps slower.... We know that the Q trans pumps thru the cooler about 4 quarts/min... However, not all Q trans are the same but its close... Should take 10 mins to do a flush! If it takes 11-12-13 your trans is weak....

Remember also you dont want only 14 quarts, youd want probably 20 at least so that you can do that little bit extra and so it doesnt run out.

Home brew things that involve plastic bags, transmission fluid, and a large bucket shoudl never be involved with the Q, IMO... By the time you got done fighting it, you could have been back from the trans shop at home reading the posts on NICO...

ceningolmo wrote:If it were simply "sucking" fluid in as the tranny was "pushing" fluid out then all we would need to do is set up an empty container to catch old fluid and a container of new fluid to get sucked in to the system. But, that's not how it works....or, at least I don't think that is how it works.

That's absolutely correct. Many years ago I made a 5 gallon bucket with a barbed nozzle out of the bottom of it in the hopes that I could hook it into the input line from the transmission cooler and it would suck the fluid in. The first time I hooked it up I accidentally hooked the "outlet" from the transmission to the cooler - resulting in a nice ATF shower. Then, when I connected it correctly, I found that the pump didn't "suck" fluid in...

I think what you're describing for your idea is basically what a BG or other transmission flush "machine" is and does...

The problem as I see it is both the one you brought up... will the fluid that you push out put enough pressure on the fresh fluid bag, and where will you find bags that can stand up to that sort of pressure, heat, and chemical composition? It would really suck having a bag melt or disintegrate on you and end up with plastic stuff in your transmission.

I think this one is better left up to either a machine or Wes's drain/fill/drain/fill method.

That said, if you figure it out and it works - please post pics!

Heath

The cooler output does not go directly to the pan, it goes to the rear planetary gear which easily starves and galls then a major portion of it flows into the pan

The pressures are 20-30 psi out and in which needs to be maintained.

Study the diagram in FSM!!!!!

I am about to explain how it is done at most shops. I work at one, so I know this first hand.

Use some sort of measuring device, (we use two 6 quart buckets)Next remove the line from the cooler that is under preasure,Atach a hose to that line so that you can fill one of the 6 buckets with that line,Fill the other 6 quart bucket with fresh tranny fluid,

Your going to need a couple of friends to help you out for the next part.

Place a funnel in the tranny dipstick tube,have a friend start you car, while pouring the fresh fluid bucket into the funnel,have another friend count the quarts that fill the "dirty" bucket, at 6 shut the vehicle off.

do that like 3 times, connect the line back. Leave the vehicle parked but run it through every gear a couple of times with your foot on the brake, and then check the level. After that your are golden.

SlipnSliden's technique sounds like it would work well, just as long as you keep close tabs on how much is coming out, versus how much you're pouring in...

I remember having an ATF flush done on a family member's minivan a few years ago, where the flush machine consisted of little more than two fluid reserviours connected by a huge rubber bellow. This machine was unpowered, and used old pressurized fluid to force fresh fluid back into the tranny - just as ceningolmo described above.

Q45tech wrote:The cooler output does not go directly to the pan, it goes to the rear planetary gear which easily starves and galls then a major portion of it flows into the pan

And it only taks a few seconds for this to happen .

It's called a Sprag Gear and when it goes, things are bad .

that method when you remove a hose with the engine running makes me nervous... The drain/refill method that I outlined will be just as good if not better, and no chance of starving anything.

http://www.bgfindashop.com

There is a reason dual bladder machines are made for this.

Home brew risk high, reward low.

Hey I have been chewing with this idea some time. At the moment I am thinking I will flush the tranny out with kerosine,

Any rhoughts?

Don't smoke and don't drive it!
Modified by maxnix at 11:54 AM 5/20/2009

I don't think I would try that - unless you've tried all of the usual commercially recommended ways, and this is a last-ditch effort before you junk it.

Heath

4-5 back to back drain and fills with a few miles driving in between will effectivly replace 85-90%+ of your old ATF with new......simple as unscrewing the drainplug!!!

derg wrote:Hey I have been chewing with this idea some time. At the moment I am thinking I will flush the tranny out with kerosine,

Any rhoughts?

I've never heard of kerosene used to clean transmissions. How does that work?

I went to a BG shop, got my flush with the machine, and everything was great. I'm probably due for another one soon.

Sometimes one must ignore newies remarks until they prove by years of service and thousands of post [and the thousand HOURS of required DOCUMENTED research] that their comments are valid from a engineering perspective.

While Kerosene may cause little damage [who knows] it cannot be considered an adequate LUBRICANT in any stretch of imagination.Almost the functional equivalent of replacing engine oil with gasoline.

11 ounces of BG Quick Clean might be somewhat similiar to Kerosene except the BG has a lower peak evaporation point when added to 175F ATF.

Luckily 11 ounces in 10 quarts is only 11/320= 3.5%

qship96 wrote:4-5 back to back drain and fills with a few miles driving in between will effectivly replace 85-90%+ of your old ATF with new......simple as unscrewing the drainplug!!!

How many quarts is that total?