I have a 1999 Acura CL 2.3 with 135,000 miles on it. It is pretty dirty under the valve cover so I decided to use some Auto-RX.
Before I used it i had the O-ring on the distributor replaced as it was starting to leak. My mechanic replaced the o-ring and I drove the car for 2,000 miles with no issues. I then changed the oil and added auto rx to dino oil. Within 2 weeks I was a quart down. I thought this was odd and topped it off. Another 2 weeks and I was a quart down again and now I could see the engine under the distributor was COVERED in oil.
It is leaking out the distributor worse than before the seal was replaced!! I called my mechanic and explained what I did. He was none too pleased. He has never heard of Auto-RX and basically views it as all the others. He said the most you should ever do is add a quart of tranny fluid to gently clean the engine and I said that is how this stuff works. He said bring it in and he will look at it, but I can tell he is pissed. Should I just continue through the cycle and see if it stops after the rinse or have them pull the distributor out and replaced the o-ring again?
-- Edited by dbdeland on Monday 22nd of March 2010 12:52:31 PM
For a leak that severe I would have him look at it right away, and would not assume the problem is the o-ring, unless the mechanic made a mistake.
For old engines it is not uncommon for autorx to precipitate a leak, however the leak will be measureable in drops not quarts, and it happens when sludge is removed from in-between a seal and metal. If he did his job correctly when he replaced the o-ring he cleaned the metal surrounding it, and there is no way for autorx to impact a new o-ring which is surrounded by clean metal. I bet this leak is something else, or maybe he did not properly re-assemble the distributor.
-- Edited by Frank Miller on Monday 22nd of March 2010 12:54:18 PM
-- Edited by Frank Miller on Monday 22nd of March 2010 12:55:58 PM
As Johnoh has stated ARX is not the cause of your distributor oil leak. If it turns out that the leak is coming from the o-ring area either the mating surface was not clean or the o-ring was not seated properly. Perhaps even the wrong size o-ring was used.
The idea that ATF makes a good cleaner is a myth. The only value it might have is in thinning down the oil. If that was your intent you'd be much better off using thin oil.
This may not have anything to do with your distributor leak but a malfunctioning PCV valve can lead to oil leaks because it allows blow-by gasses to over pressurize the engine.
-- Edited by Frank Miller on Monday 22nd of March 2010 12:56:50 PM
guys thanks for your replies. here's my problem though... after he replaced the o-ring i drove 2,000 miles with NO PROBLEMS. I put auto-rx in and bam within a week i'm leaking oil. my thoughts are he did a proper install but ultimately the o-ring was seated against sludge and not clean metal. if you think about it the distributor goes way down inside the engine so it would be difficult to clean down there. let's assume what i said is true, that the o-ring was seated against sludge that has now been removed... how then can i get this to stop? i called the company and they said just keep topping the oil off and the leak will stop during the rinse cycle. the guy then said that the ring may be too pliable now (WTF does that mean) that's just plain stupid. I could see having issues with an old ring but this ring only had 2,000 miles on it. the o-ring ultimately should still be sealing against the metal. maybe it is leaking somewhere else in the distributor. thoughts?
remember that a new o-ring is way more pliable than an old one. If a new one was seated against sludge and the sludge then removed, it would not leak for long or with much severity because the pliability of the new o-ring would tend to quickly seal the gap created when the sludge was removed. If you are leaking at that seal, its either the wrong seal or its not properly installed. But you're probably leaking elsewhere.
A general autorx rule is that if a leak starts when using autorx, be patient and it will stop during the rinse cycle. But your case is unusual and you are losing too much oil too quickly, and should have it diagnosed
Might I suggest you check out your PCV valve and hose. Excessive crankcase pressure could be forcing oil out of the o-ring seal. If the inside of the valve cover was pretty grungy it's possible that the PCV area could be plugged. If in doubt replace it. Shaking it and hearing it rattle doesn't mean it's working.
thanks for asking, replying to the thread was on today's to do list :)
the mechanic ordered a factory o-ring from honda and pulled the distributor and replaced it. i asked the shop manage what was wrong or what would cause it to fail and he said they were very busy and he didn't have a chance to look at it. i didn't want to pester him because they wound up not charging me a dime!!! my guess is the after market o-ring didn't fit as good as the factory one, which is why he went straight for a factory o-ring this time. or maybe it wasn't seated properly and the auto-rx cleaned off some goop it was against. i guess we will really never know. i'm just glad it isn't leaking anymore. it was dumping some serious oil out and based on that it would be hard to think it was simply the auto-rx. the auto-rx may have simply brought to light the fact the o-ring wasn't completely correct.
they put some leak detect in the oil and in a week we will black light the engine to make sure it is all ok.
Kudos for getting to the root of the issue. As you could tell by the reaction from the mechanic it's often a knee jerk reaction to blame whatever you changed in the mix. You'll get this from anyone from supervisors to service managers. It's a typical reaction when blame needs to be assigned anywhere but where it should It usually goes like this:
"Did you do anything different?"
"Well, the only thing I can think of is that I sneezed when I put it in gear"
"THAT'S IT!!!!!!! You clearly destroyed the thing! Everyone knows that you don't sneeze when putting it in gear! You're fired!!" (insert warranty denied/whatever)
these guys are pretty cool though. he is def old school and likes transmission fluid to do the flush. i think when he took a look at how much oil was coming out he realized it wasn't what i put in the engine that caused it.
Turn him on to Auto-Rx. ATF is only a thinning agent. The semi-myth was formed when GM issues a TSB in the late 60's/early 70's recommending it for lifter noise in small block Chevy's. It was a thinning agent. Since many observed that it indeed quieted the lifters, they integrated that it cleaned a clogged oil passage. It had nothing to do with clogged passages and everything to do with lube system design and manufacturing variables (oils of the day had something to do with it too).
There are no detergents in ATF ..or very little, any way. The only thing going for it, if you can call it that, is that it can be more tolerated over longer drains since it's not a solvent. It's great if you want to whip your existing oil around a bit more. You could do the same by using a lower viscosity oil for all the good it will do.
ATF was also used on the combustion side of the equation. You would suck in a quart of ATF to clean the combustion chambers. This works. The practice was formed by having a leaking vacuum modulator, which was typically tapped into one intake runner drip ATF into the intake stream of an engine. When the heads needed to be pulled, that cylinder/piston/combustion chamber was clean compared to any engine that had required the heads to be pulled. Carbs were lousy as they aged and carbon encrusted pistons were common. The ATF drip was an upper cylinder lube and produced an insulating layer allowing the excess fuel components to take a trip out the exhaust. Marvel Mystery Oil was used in this manner with their Inverse Oiler. The practice was made obsolete with the advent of unleaded fuel, fuel injection, and better ignition systems.
There are also ash components to ATF that would not be wise to introduce into your exhaust stream. That's from a purists perspective.
Yeah, it's a common misconception. There's no reason to have dispersants and detergents in ATF. They're used to suspend combustion byproducts/insolubles. It keeps them from forming up and getting large enough to be abrasive. The term "detergent" isn't synonymous with "cleaner" in a motor oil. It's to keep stuff in suspension. Ideally stuff is kept suspended or it's filtered. Combustion byproducts are the chief element that loads your oil filter. That's why some OEM's recommend every other oil change for a filter change if mileage is used. If you're doing over a certain amount of mileage in a given time frame, you have to have less fuel enrichment miles out of your total mileage. The post fuel enrichment miles are mostly hollow as far as filtration is concerned (in gas engines, anyway).
I understand about old school types. My favorite former racer/engine builder/wrench and local race/wrench hero will occasionally ask me about something he read or heard about in terms of lubrication. As soon as I get a bit too deep the subject changes. A wrench has his hands full just keeping up with changing technology. Even when they're not going to see a given model for the first 3 or 4 years, they have to learn it sooner or later, or just opt out and refer the customer elsewhere.
Most old school types learned about lubricants once back in the 70's. From there on out that image was cast in stone. The whole petroleum industry has been reinvented and reinvented again and is about to be reinvented again. What was true than is often not true now.
geeaea wrote:Most old school types learned about lubricants once back in the 70's. From there on out that image was cast in stone. The whole petroleum industry has been reinvented and reinvented again and is about to be reinvented again. What was true than is often not true now.
Excellent point, and applicable in many areas other than oil.
guys thanks for all your input guys i really appreciate it. now i have a tranny question. i will post it in the forum but i'll mention it here as well since i have an audience :)
same car 1999 acura cl 2.3. automatic tranny. 136k on car and tranny. this is my girlfriend's car and she has been noticing something. today she was driving down the highway at a steady speed and all of the sudden the rpms jumped and the tranny downshifted while she was driving and she had not moved her foot on the gas pedal at all. my guess is i've got tranny problems. i want to do an auto-rx treatment and a professional tranny flush to see if it will help. questions are...
just add the auto-rx to the tranny and drive 1,000 miles than have the professional flush?
and
what if i can not change the filter? the filter on these trannys are internal and you need to drop the tranny to get at it.
since the o-ring was replaced my girlfriend has driven the car 500 miles in 5 days and she is a 1/2 quart low on oil. the o-ring is no longer leaking and i see nothing dripping under the car while on my knees (i can't get under the car right now). i am getting a little worried because before the auto-rx treatment the oil was CONSTANT, never dropped over a period of 2,000 miles. any thoughts? in 700 miles i will be changing the oil for the rinse phase. my mechanic also put an additive in to check for leaks. we will be black lighting it this coming thursday or friday.
Relax, Mike. I assure you that Auto-Rx did no harm in doing its assigned task. Without further evidence of leakage just wait it out and allow the full process to be completed.
You can run into this same effect when switching from (something like) a long bout of conventional or Group III synthetic oils to something like Redline or a PAO like Amsoil ..or the other way around. It's termed transitional consumption. It's the disruption that can occur at times when switching chemistry. Auto-Rx is designed to do just that, disrupt existing formations.
Your consumption should settle down in time. Your condition, while not typical, isn't unheard of. The self test you subject yourself to is to ask: Has there been any mechanical trauma since the consumption evidenced itself? YES or NO. If YES, then you have just cause for concern. If NO, then one would attribute it to changing conditions that did not involve changes in mechanical condition.
I changed oil from Delvac 1 (a PAO) to Rotella T Synthetic. I had no consumption with Delvac 1 for over 10,000 miles. I consumed my first quart of Rotella in 3000 miles. I was freaked, but reasoned that nothing had occurred or changed except the oil. My consumption retreated to 6000 miles/quart and then to 9000 per quart. That was good enough for me and I then settled for 6 months which was about the 9000 mile mark.
1/2 quart in 500 miles is a lot for a leak and the mechanic will probably find the leak due to the flourescent additive. Leaks are a common annoyance on cars 10+ years old so I would try not to be too concerned for now. And whatever the mechanic says, you do have the option of waiting it out. I've used autorx on a dozen cars that age and I usually do get a new leak, but every time the leak has ended during the 1st or 2nd rinse phase.
geeaea thanks for the info. to answer your question nothing mechanical has changed. what you said makes a lot of sense. the o-ring issue, while still somewhat of a mystery, i am chalking up to a bad aftermarket ring that may have been impacted by the auto-rx.
regardless the mechaninc made good on the repair with a factory o-ring and i will follow up with him and his black light at the end of this week. if we see no evidence of leakage than i will chalk this up to consumption based on new chemistry as you said.
i will finish off the clean cycle and follow it with a rinse and then since i am at 135,000 miles i will go right into a second clean cycle and then a final rinse.
on a side note i've thought of putting both my cars on a synthetic diet after their auto-rx treatments but after reading this forum i've had second thoughts due to the things i've heard on seals and synthetics. but i heard this could be cured by using 2 ounces of rx with every oil change of synthetic.
Yes, mike, all oils form coke formations in the ring area. Some take longer than others to form. Some take longer to be displaced. In the interim, you can experience consumption.
Good luck with the leak test. I hope that you visits to the shop for this issue are over with.
not trying to beat a dead horse but could you explain the coke formations a little? how would that cause consumption based on changing oils or using additives?
Oil migrates to the upper ring area. There the temps are extremely high. The oil is the only thing that cools the piston besides the intake charge.
Side note: While ring gaps are oriented 180 degrees out of each other during assembly, there is no assurance that this orientation is maintained for the rest of the life of the engine. Rings dance around in a circle. They do tend to stay in enough of a non-alignment to facilitate proper ring seal and limit blow by. Most consumption (assuming all things are functional - PCV, etc. ), in the absence of neglect or some insult (overheat, for example), or perhaps a design characteristic, is typically due to this
This migrated oil will form deposits. It's a YMMV situation in terms of severity but occurs to some degree in all engines. The difference in base oil or additive package effectively out muscles the bond that the spent/burnt material has to adhere to the metal and stay integrated.
It's not so common when changing oils, at least in terms of discovery. You'll sometimes here of someone trying a new oil and they'll say that they switched back due to consuming oil when they used the new brand. If they had stayed the course, especially with contemporary oils, the condition would most likely correct itself in due time. They can't see beyond that initial consumption nor analyze whether it's linear, progressive, or retreating, nor would anyone expect them to.
-- Edited by geeaea on Monday 22nd of March 2010 08:20:59 AM
geeaea.... WOW you really seem to know your oil issues or are just a really good BS... lol just kidding :)
seriously thanks for your advice, i really do appreciate it. i sort of entered freak out mode when my consumption went up but your advice and info makes sense and i will stay the course.
i will post back later this week when i take the car to the shop to black light it and see if we find anything.
the main thing i am concerned about there is that the cam and crank seals were replaced same time that o-ring was the first go around. even before i put auto-rx in i noticed a drip out the timing belt cover weep hole. i chalked it up to residual oil from the repair. i wiped it clean and then 1700 miles later it appeared again (this time with rx in) so we are a little concerned that the new seals may be leaking a little bit due to who knows what. the dye will reveal if this is the case... i hope.
-- Edited by dbdeland on Monday 22nd of March 2010 12:42:23 PM
I have a 1999 Acura CL 2.3 with 135,000 miles on it. It is pretty dirty under the valve cover so I decided to use some Auto-RX.
Before I used it i had the O-ring on the distributor replaced as it was starting to leak. My mechanic replaced the o-ring and I drove the car for 2,000 miles with no issues. I then changed the oil and added auto rx to dino oil. Within 2 weeks I was a quart down. I thought this was odd and topped it off. Another 2 weeks and I was a quart down again and now I could see the engine under the distributor was COVERED in oil.
It is leaking out the distributor worse than before the seal was replaced!! I called my mechanic and explained what I did. He was none too pleased. He has never heard of Auto-RX and basically views it as all the others. He said the most you should ever do is add a quart of tranny fluid to gently clean the engine and I said that is how this stuff works. He said bring it in and he will look at it, but I can tell he is pissed. Should I just continue through the cycle and see if it stops after the rinse or have them pull the distributor out and replaced the o-ring again?
-- Edited by Frank Miller on Monday 22nd of March 2010 12:55:02 PM
ok was back at shop today and it looks like the leak is fixed. a little bit of residual left over oil when i wiped my hand under the distributor but the mechanic said that is normal as any oil that wasn't cleaned up works it's way out. he said there are tons of nooks and crannies that can hold oil and it just takes time to come out. AND most importantly we shined a blacklight on my hand after wiping the distributor and it didn't fluoresce so we know it wasn't from a leak.
on a side note i think i discovered my "consumption" that geeaea spoke of. my friend was behind me today and i gunned it and he said blue/grey smoke came out and it smelled like oil. my guess is during the cleaning phase i am getting oil past the rings or valve stem seals and i hope this will stop when i enter the rinse phase.
with a 138k miles on the engine and running auto-rx through it would this be considered normal?
btw... i am very grateful to all who have replied. your support and answers have helped.
just a side note - you might clean off that engine. Here's one method:
- put your car outside of your garage first to avoid soaking the floor with grease/oil/dirt - use a can of engine degreaser on your barely warm engine, spraying the entirety of the engine area (careful about getting it on paint though), including spraying upwards from the underneath the car, and whereever else you can possibly reach (if the engine is hot the degreaser runs off too quickly and does not penetrate) - lightly hose down with water after 10 minutes. - wipe off everywhere using shop rags - using a flashlight and Simple Green (or carb cleaner on tough spots), go over any trouble spots one more time - take your time to be thorough
Your engine is now easier to work on since you can see things more clearly, its much easier to detect new odors, and its better for the belts and hoses to be clean, and you don't get gunk on your hands just because you touched your engine while checking your air filter or whatever. After this, plus two autorx cycles, your engine will look, drive and smell about 100,000 miles younger than when you started. Its a good feeling.
It does not make sense to me that any car would go from zero oil consumption to high oil consumption just by using autorx. Hopefully that was due to the o-ring
-- Edited by johnoh on Thursday 25th of March 2010 01:20:42 PM
thanks for the info. i keep my engines to the point where you can eat off them :) for the very reasons you stated above. i left the engine alone for this past week so the mechanic could examine it as he left it. he got 90% of the oil off and wiped it down good a week ago and i left it alone since he was still checking it. now i will give it the go over and make it real clean. makes like way easier when working in it.
do you think it's normal to be burning oil during the cleaning phase? i actually burned off 1/2 quart in 500 miles last week. i being told (and it does make sense) that this is normal due to changing what the engine is used to in the way of oil.
i agree with what geeaea said but it's never a good feeling seeing smoke out the tail pipe when you jump on it.
well i am finishing the cleaning phase this weekend. now will be entering the rinse phase. but first a seafoam treatment of the intake :)
what the heck i will keep tabs here and post how the oil consumption goes during cleaning. looking forward to pulling the valve cover soon too to replace the gasket and also take a peak under there.
my own experience on this point is limited to a dozen cars, but I have never seen a consumption increase with autorx, and in fact quite the opposite.
Sure, but they were (probably) already consuming oil. Ring coking may or may not produce consumption, even if compression is somewhat compromised. Many also change their oil in short enough intervals to mask the rate of consumption.
well i am now officially in the clean phase. just had the oil changed yesterday and while i hate taking it somewhere to get the oil changed i had to give in and have that done yesterday.
these guys always seem to overfill!!! it looks to be 1/2 qt. or less overfilled. do you think this is anything to be concerned about? i know some guys are like that will ruin your seals! and others are like it's no big deal.
btw... i saved the oil filter from the last normal oil change PRE auto-rx and i saved the oil filter from the half way change (about 1700 miles) during the auto-rx cleanse. i will be cutting them open one of these days and i will take some pics and share.
if i remember correctly i checked it this weekend before the oil change and it looked steady. the real test will now be to wait these 3,000 miles of the rinse phase and see how it goes. i will be checking it weekly to see if consumption goes on like it was.
on a side note what do you think about them overfilling it around 1/2 qt. or less? anything to really be concerned about?
Some over fill is not a problem. The only time I've ever had issue with it was with my BMW 320i if I was pushing it to the redline and then backing off (high vacuum). It would produce a puff of smoke due to the high vacuum pulling the whipped up oil into the upper ring area. This was at low mileage on the engine. Less than a year old. It was a quart overfilled. No residual effects.
This was an issue of merit at one point when there was a transition to lower profile cars. Squishing the pan was one method of getting too big an engine into too small a chassis. One Mustang, iirc, had two drain plugs. The pan wrapped around/over the cross member. Often the oil changer would pull the first plug he saw, button it back up and add the full amount of oil.
I haven't seen or heard of reported problems over the last couple of decades. Bulk dispensing systems may have indeed improved, but one would think that this would still show itself at some point.
The only thing I would recommend is waiting until the level is in the range of the normal measurement (FULL:ADD) before calculating consumption. That windage that I reported, if present, may make it easier to send oil out the PCV system.
But it may not be an issue at all.
-- Edited by geeaea on Tuesday 30th of March 2010 08:17:38 PM
-- Edited by geeaea on Tuesday 30th of March 2010 08:20:02 PM
been doing some thinking on the oil consumption. it is still consuming but does seem to be calming down. hard to say right now since the car is being driven slightly less than the crazy high miles my GF was putting on it. i will def keep you posted. right now half way through the rinse phase.
here is my question. i've been using 5w30 in it. well the engine has 150k on it and i live in NC where the summers get hot. would it be wise to go to 10w30 or even 10w40 to help with the oil consumption (burning)?
i will be doing a second auto-rx treatment in 1500 miles and would prefer to keep it in the crankcase and not out the tailpipe. hence the heavier oil idea.
i would go to a 10W-30 for the next cleaning cycle, while monitoring oil consumption. If consumption settles down, then stay with that viscosity for the rinse. If it is still too high for your liking, then you could use a 10W-40 or 15W-40 for the rinse.
My buddy ran 2 treatments through his Acura 2.5 TL with 200k miles on it. He was using/leaking a quart of M1 5W-30 every 1500 miles. By the time he was done, he had his rear main leak down to a slight drip and consumption down to a quart every 2500 miles.
He then dropped consumption down even further to 1 quart every 3500-4000 miles using Maxlife 10W-40 and a 4 oz ARX maintenance dose. Part of that was due to the rear main seal stopped leaking altogether and he can park in his driveway again without putting cardboard under it. He changes this oil every 5000 miles and is currently at 230k miles. He plans to drive it until it reaches 300-400k miles, if possible. We also treated the trans and pwr steering at the same time. Did I mention that his car runs like a new car?
BTW, we added an inline filter to the return lines of both the power steering and transmission fluid systems and a large aux cooler to the trans cooling as well.
-- Edited by bmwtechguy on Friday 16th of April 2010 08:04:41 PM
dude thanks for the info! i agree with what you wrote and think it makes good sense.
the trannies in those CLs are known to shift really hard and be noisy (which hers is). i plan on running some auto-rx in the tranny and then having my mechanic do a complete flush/swap with his machine after 3,000 miles. the reason i chose 3k and not 1k is because on the apps page they say for high mileage or hard driving go 3k. she is putting some serious miles on her car... sometimes 500 a week so i'd consider that high mileage.
they say to run 6oz in the tranny. what did you guys run?
bmwtechguy in regards to your buddies acura... auto-rx recommends you change or clean the tranny filter after a treatment. i know in the CL the filter is in the tranny where you actually have to drop the tranny to get at it. obviously that ain't gonna happen! i assume the TL is the same way.
A - did you drop the tranny to clean the filter? if so how did it look?
B - you said you installed a filter on the return line of the tranny. i assume you are referring to the 2 lines that run from the top of the tranny to the base of the radiator to cool the fluid. how do you know which is the return line? where did you pick up a tranny filter like that?
those transmissions are known to have problems. mine is starting to shift real hard when it is cold... about the first 10-15 mins of driving. right before it shifts into the next geer it will tack up like 500 rpms and then shift hard. so it is this annoying reving, then shift then rev then shift. make sense?
His tends to do the same revving thing you talk about. We used the Honda Z1 fluid, then added about 4 oz of some Lubegard black, which is a friction modifier. This helped to tame down his harsh shifts. I'm not telling you to do the same, just what we did. You still sort of have to let it shift before getting into the throttle or it does rev somewhat (not a flare-up, just goes higher revs than I am used to). At least the shifts are a bit smoother. Of course this was after the Auto-Rx treatment and flush through the transmission lines you mention.
To figure out which way the fluid was going, I just took both lines off and put a hose on each and directed the other ends into a fluid container and had him start up the engine for a few seconds to see which one the fluid was coming from. We did not drop the transmission and had no problems.
I use 2 different brands of inline filters for pwr steering and transmission fluid. Magnefine and SPX/Filtran. I order them online in quantity to get a better price. Google search. Most auto stores do not stock these items. Some transmission shops carry them, but want $25 or more each. I usually pay around $15/ea or less with tax/ship included. Get the 3/8"" size if you do buy one.
thanks for the info it is greatly appreciated. this forum has been invaluable.
as for the others who are watching this thread the leaking distributor mystery is solved. it turns out that while the o-ring was bad the distributor itself is leaking through the shaft seal. mystery solved... time to replace the distributor.
@ bmwtechguy - i have the auto-rx in the tranny right now. when it came time to flush it how did you do it? did you take it to a shop and have them flush it or did you do it yourself? in the acura forum i read some guys saying DO NOT hook it to a flush machine as many have had problems with these trannies but rather buy 9 quarts, drain 3 and fill it... run the car.... drain 3 and fill it run etc... then in essence you will have swapped everything out in the entire trans.
tomorrow i get the new distributor put on to solve the leak. in about another 1500 it's time for more auto-rx and going to 10w-30 now.
I never use a flush machine, but my method accomplishes the same thing, which is to safely replace all of the fluid in the transmission. I drained it and then refilled, then removed a hose from the fluid cooler path to or from the radiator. An extra length of hose, even a clear hose is pushed onto the now bare radiator connection and then direct both hoses into an empty fluid container. Have an assistant to start the car briefly as you watch to see which hose the fluid comes out of. Now using the hose that the fluid came out of, restart engine and pump out this fluid until the flow slows down a bit, stop the engine and refill the trans with 3-4 more quarts. Start back up and do again until the fluid coming out of the hose changes to the new fluid color and smell, or stop when you have drained/pumped out the known or listed capacity of the unit. On some cars, I have used one more qt than it holds due to some mixing as you are doing this cooler line flush.
Then reconnect your cooler line(s) back as before and refill unit to correct level. Test drive and then recheck level. You are done. The partial drain method that some people use, works well if you can get a large percentage of the fluid out during a drain. Some cars you only get out about half of the fluid, so you end of wasting a bunch of new fluid overall, and getting less fluid changed out altogether vs the cooler line flush. Either way works and some people just find it easier and feel safer doing multiple drain and refills. The choice is yours.
thanks for the info. i do have a couple of questions. it does sound like your method is a bit more thorough. if i drain the pan out and replace with the same amount, run the car, drain the pan, refill etc... until i use the total amount of quarts in THEORY i should have swapped most of the fluid. but since the fresh is mixing with the old in this process it isn't 100%.
your way sounds a little more thorough. since you are catching the old fluid out of the pump and maybe even on the output side of the cooler (depending which line you disconnected). in other words you know that stuff is dirty and hasn't seen the clean fluid yet at least for one or two of the fluid swaps. so is your way a little bit better?
my other question is is it dangerous to run the car and allow the pump to pump out the fluid until it trickles down? do you run the risk of damaging the pump or internals of the tranny as the fluid rapidly drops since the line is disconnected and pumping it out into a bucket?
here's an idea too... what if you figure out which way the fluid flows and disconnect the hose that is returning the fluid from the radiator to the trans. in other words the furthest point from the system in the return loop. now run that line into a bucket and start the car. as the fluid is continaully pumped out immediately pour fresh fluid into the trans. the only flaw with this idea is if the pumps picks up your new fluid right away and it doesn't make it into the torque converter. which would mean you actaully need to run the car around to get the fresh fluid up into the torque converter.