Flushes are pretty straightforward. You disconnect the return line from the ATF cooler. Direct that line to a drain pan, preferably one with measurement marks. If you have only one person then start the engine and stop it when you've pumped out a qt. Now add a qt through the filler. Continue until the ATF looks new or you've flushed the full capacity plus a qt or two. Make sure to add the same amount you removed. If you have more than one person then they can run the engine while you add ATF but be careful not to let the pump run dry, better to pump out a qt or two and stop the engine to catch up.

The flush machines work by the same concept. The return line from the tranny cooler goes to the flush machine, and then a line from the flush machine goes back to the transmission. As the old fluid pumps out to the flush machine new fluid is passed to the transmission. Both the machine and the DIY steps rely on the ATF pump to do the work.


Anyone tried this method, sounds safe, but like to know from the experts, thanks.

Above taken from cartrackers.


Thanks

 

I would say the above method is risky. It is better tp have the right plumbing where you introduce the same amount as you let out.

I would not risk, introducing air in the sytem, pump running dry or the torque convertor running with less than full.

Salim.

 

Salim,
Tranny is not air tight by any means, dip stick itself introduce a nice vent hole for air to freely enter/exit the transmission system.
I think anyone who is incapable of adding a quart or two ATF when disconnecting the tranny cooler should not do any DIY work. It is as easy as pumping gas.
Also, I would like to hear why drain and fill is not a risky method. Replacing 4 out of 9.8 quarts of ATF is equivalent of replacing 2 out of 5 quarts of engine oil. Anyone happy with 60% dirty oil and call it a safe oil change?

 

Salim,

I'm under the impression that the pump is above the drain pan, and there is air, introduced through the dipstick.

If we modify it like the attached pdf, your concern about air being sucked in gets eliminated.

From the return used ATF gets collected in a container (in picture brown football). Using another hose attached to the return port of radiator introduce fresh AFT (in picture pink football).

With the SUV started and in park, the tranny ejects used ATF and if there is enough pump suction, it will suck up new ATF. If not just fill through dipstick what came out.

Thoughts on this modified approach.

 

A few days back there was show on Discovery HD, where some one was putting together a cross terrain in war torn Iraq. Mechanic installed the torque convertor without priming it. When they tried to run it, in 30sec or less the transmission broke down.

Even when the level above the fluid line is open to air, the circuit is primed. When you drain and fill, you can introduce a bubble in the riser line (before pump) but that would be pumped out.

I am not proposing that the flush will be permanently harmful, I am saying it is risky. I try to err on the side of "less risky" ... specially if it is something that I have never done so on my own.

Salim

 

In Salim's defence,

I agree that by far the concept of draining the trani fluid (whatever percentage you do from a conventional drain) is safer than disconnecting a trani return line and introducing new fluid via this method.... which co-incidentally you can't monitor the fill level unit it is done and then might involve partial drain anyway...

Most people that frequent this forum and have had the opportunity of reading the trani flush/ drain and fill posts will know where the front differencial is or at least know where the trani drain is located and by using logic, will agree that if you drain 4 litres and put back through the dipstick another 4 litres, it is much easier than disconnecting a trani line...
BTW I consider myself a reasonable DIY kind of person and wouldn't be bothered looking for or disconnecting any trani lines...

Sure the drain and fill is not a complete flush... If you only do it once.

However, given the realative ease in the process, I think anyone who can do it once, can do it again a couple of more time to in fact drain all the fluid.

The amount of fluid needed for 3 drain and fills is not much more than that needed for a complete flush and besides the logic behind drain and fills was do it once every 30,000 km and you shouldn't have a problem.

I would rather drain and fill every 30000km than leave it in for 100,000km and then do a complete flush. Mine was in there for 80,000km and I saw the amount of sludge that was in there.


You have to agree that the level of knowledge needed for a drain and fill through the trani dipstick is different from the knowledge of properly locating, disconnecting and reconnecting the trani lines, all while introducing new fluid.

 

I really have no problem with drain and fill or tranny cooler disconnect, both procedures serve different needs. But let's not make blanket statements such as A is risky and B is safe, especially when pro and cons are not discussed.

I have done the tranny disconnect, get 2 additional quarters out of TC for a total 7 quarts replacement, after I did a drain and fill and replaced tranny filter (5 quarts replaced). Remember our tranny filter is more of a screen than filter, the only way to get rid of scrub buildup is to replace ATF. The higher % of dirty ATF replaced, less frequent ATF service interval is needed during one's ownership period.

Drain and fill is easy and proven, but doing 2x or 3x after the intial one will waste some of the fresh ATF you just poured in. Draining out fresh ATF and keeping the dirty ATF are significant drawbacks. Quick math, 2x drain and fill requires 8 quarts ATF to replace 64% of the dirty fluid, tranny cooler disconnect requires 7 quarts ATF to replace 70%. There is no secret why drain and fill needs more ATF but achieved lower % replacement: fresh ATF is drained out instead of dirty ATF.

Monitoring the fluid level is easy, cooler return line to the tranny can be inserted into an empty ATF bottle. When the bottle is nearly filled, just swap with another empty ATF bottle. To fill ATF, you can stop the car and fill one quart of ATF, or ask your helper to pour it down the dipstick. Again, as easy as pumping fuel, just aim and dispense the fluid.
Yes, one needs to go the extra work to disconnect tranny cooler line, but additional work also needs to be perform with mutliples drain and fill: didn't you have to drive around, get under the car, loosen drain plug, fill ATF, 2x or 3x times?

On bubbling in the ATF, since the car is in constant motion, bubbles will form when ATF is stirred during driving. If you don't believe it, pour some ATF into a cup and stir it with a coffee stick, tell us what you see.

The most amazing thing is when I dump those 7 bottles of ATF at local Kragens recycling oil tank, the bottom of each bottle is covered with a layer of black fine metal debris. These particles cling to the bottom and can not be drained off when ATF is stirred up and emptied.
I prefer tranny disconnect procedure because it get the maximum metal debris out of the tranny while wasting little fresh ATF.

 

Just wondering if you have the same trans dipstick setup as I do. My trans dipstick has a rubber o-ring on it which seats in the dipstick tube and a metal clip which holds it there. Not looking to debate how much psi this will hold and for how long but I wouldn't exactly call it a vent for air to freely enter/exit. But even if this was open the system is designed so the pump does not suck air. But I believe what Salim is saying that running the fluid low during a back yard flush may introduce air to the pump. I think I will stick with drain and fills.

 

I am not rying to debate the issue but the intent is make the readers aware of a potential risk. There is a definate ditinciton between work and risk. The risk is the one that worries me.

If others think the following two do not pose a problem, then it would boil down to convinience (work) and advantages (technical and financial) and fluid waste.

1. Can they introduce new fluid as they drain, at the same rate [there can be a marginal difference].

2. Do any component run without enough T fluid in them to cause damamge.


I think with care 1 can be accomplished. Lacking thorough knowledge, I can not answer 2, specially when you open a line and pump nothing through the other end. Maybe caping it would serve the purpose ... but then again a thorough knowledge is needed.

My rudamentary understanding of flush machines is that they progressively introduce cleansing_agent (which lubricates too) to purge out old fluid. Then they purge out the cleansing_agent with the new fluid. All this is done without running anything dry or low. This succesive purging can be done with the transimssion pump (safer) or with an auxillary pump (needs pressure calibration).

mtom01 was inquiring how safe it was and I shared my reservations.


Salim

 

just a quick note for do-it-yourselfers, the rx300 is DIRTY. on average we use about 20 litres of t4 to get the system "clean". ask your dealer what system they use. Most are perfectly safe. If you want to be a little more causious, ask that the do not use the "flushing" agent, just straight trans. fluid.

 

Different opinions are welcome and it is why we have this forum. But opinions are more valuable if they are substantiated with your actual experience (datum of one) or better yet independent reported cases (data from many).

The reason for me to ask is I have done drain and fill and cooler line disconnect method, after 15K miles nothing but good experience. I have never heard any reported case of tranny problem on this cooler disconnect method. My DIY thread is
https://www.clublexus.com/forums/sho...d.php?t=220061
Now I would like to hear anyone else that performed the task themselves but found additional risk/problem? If one has not done the cooler disconnect method himself but heard a reported case that showed additional risk, please post. I just want to find out about fact, even it is data showing the opposing view.

Filter Council warned against using T-Tec machine for flush because it clogged the tranny felt filter.
http://www.amsoil.com/lit/filter_man_council01.pdf

Cooler return line to the tranny is the last leg of connect to return ATF on the way to the pan before ATF is picked up. There is no way pump will ran dry when fresh ATF is introduced at reasonable rate. Ever parked on a slope and tranny failed because ATF level is slightly lower in the pan? If transmissions can not tolerate sight amount of ATF level fluctuation, the tranny design is flawed.

 

If the open line dumps in to the reservoir (pan) then it would be safe.

Salim

 

In TunedRX300's defense, I haven't seen anyone mention any actual problems based on personal experience with this particular method.

I've parked on some pretty steep slopes here in Mexico City and never encountered an issue with the tranny.