Cardesign

hello...im new to this forum. it seems like there are a lot of experienced toyota owners here that can help me. I just drained my tranny fluid today. I replaced it with mobil 1 synthetic. Is it bad to have mixed that with whatever toyota uses? The truck is a 98 4runner with 76k on it and the fluid was last changed at 35k from what i can tell. My local dealer said they dont recommend flushes and three other dealers said they do. What do you guys think about adding the mobil 1 and whether I should flush or not. I'll be driving from NY to CA soon.

hamstrungtaco

if u drive in the mud a lot i would highly recommend flushing it, if it has never been flushed at all flush it, i dunno what the scoop is on automatics, but i lost 2 syncros on my manual and had to have the tranny replaced becuz i didnt know any better back that day, i get mine flushed and its only 40$ where i go, it varies

lv4runner

I didn't realize until recently that draining and filling the tranny back up doesn't replace all the fluid. Unless you flush it, you're left with more of the original fluid then the new stuff. I don't know if mixing the two is bad. I personally have had bad luck with the dealer claiming the wrong type of fluid was used and not the recomended stuff.

Cardesign

i want to flush it but i keep hearing these nasty rumors about flushing a tranny that had crappy fluid and the tranny dying because it was familiar with the crappy fluid. i read some old threads on here saying that.

Loonz

Its never a good idea to mix oils. Nothing major, just not good.

And as far as flushing it ive done it, but likewise i have heard that it maybe bad because between flushes at the location you flush at, they may or may not have cleaned the machine between the flushes. So if the person b4 you had metal shavings in their tranny you get them also.

dunno if this helps but there you go

-David

wrenchmonster

For an AT, always use the recommended tranmission fluid. Whether that be Type F or D/M or whatever. The proper fluid will maintain the rubber and teflon seals as designed by the manufacturer. You can absolutely ruin a transmission by using an incompatible fluid.

As for the flush, the flush machines will do a better job than simply draining out the fluid from the pan and refilling. This is because the machine works with the engine running. Hence the transmission pump is working and pushing fluid through the torque converter lines and trans oil cooler. Just a drain and refill will only get the fluid in the pan. Did you take the pan off? How's the filter/screen inside?

Most flush machines use a bladder type system. So all the old fluid is evacuated out of the machine, then the machine is filled up with new ATF. When exchanging the fluid into your vehicle the machine is pushing through on one side and filling up with the other. The likely hood of contamination of the last guys fluid is very minimal, say possibly 1-3% of the last guys fluid. "Metal shavings" would be caught in the transmission filter itself and wouldn't make it to the flush machine in the first place. I wouldn't worry about that.

Now here's the old timers method. Get 2 five gallon buckets. One is filled with new ATF the other one is empty. Tap into the tranmission cooler lines. Attach 2 pieces of rubber hose and place each rubber hose into the empty bucket. Get a helper. Have the helper for just a milisecond start the motor and observe which hose is spitting out ATF. Turn off the engine. Leave the spitting hose in the empty bucket and move the other hose into the bucket with the new ATF. Now start your engine again, go through the gears to clean out the valve body and wait until the one bucket is full and the other is empty. Reconnect the cooler line and your done. Simple.

Keep in mind a few things. First, drive the vehicle around and get the tranny hot. Second, get a helper. Doing the bucket method alone can be messy to say the least. Three, some transmissions pumps will only pump enough off idle. Four, make absolutely sure that you're fluid is topped off to the correct level. Check and double check, go through the gears. You can ruin your transmission in 2 miles if not filled properly.

-Wrench

kevin444

Good Post!

Cardesign

i thought that the return linw wont suck up the new fluid and you had to actually feed it through the dipstick tube.

wrenchmonster

Hummm. I'm not understanding the question here. I re-read my post and perhaps I made a misleading remark. I said "tap into the tranny cooler lines". Well, you only have to create one opening in one of the lines. Is this what you are referring to?

Or perhaps you missed the part about some pumps not pumping enough until off idle? Some in neutral too.

The dipstick tube doesn't have anything to do with the flush operation. Please elaborate your question Cardesign if I'm not answering interpreting it correctly.

Kevin444- Thanks buddy. I'm a Kevin too, for the record.

-Wrench

kevin444

Hey, Kevin


PS: sorry for hi-jackin the thread.

So i called EZ-LUBE in regards of a tranny flush. They told me they only use 4 qts to flush out the tranny. So 15mins later I had them so-called flush it.

This is what they done.

1. Drain fluid in the tranny pan.
2. Refill with mobil atf from some sort of gun.
3. Start Motor ˟˟˟˟ through all the gears for about 5-10mins.
4. Drain tranny pan.
5. Refill with mobil atf again from that gun.
6. Started the motor and did the switching into all the gears for about 5 mins.
7. Drained the fluid again.
8. Put in about 4qts of Mobil 1 atf.

What ive noticed is why he didnt flush it from the cooler line like hookin it up to some machine. Didnt remove the pan and clean out the filter and wipe for any shaving if present.

In the meantime i figured I get my power steering flushed. So what they did was they got a siphon and sucked all the oil fluid put in new fluid. Started car turn the wheels. Did the process 1 more time and than put mobil atf into my power steering.


In a way i feel ripped off because i payed $110.. But the guy seems nice, we chatted for awhile i asked if he had a military discount and dropped the total to the price mentioned above so i guess i saved 30bucks. He also added some friction modifier additive to the tranny fluid. I asked him what is he putting in and he said to make increase the viscosity...?? He said if you dont with synthetic atf you will mess it up and im like thinking to myself that a load of BS????.. So I drove home i do notice an improvement, it shifts better and smoother. But im thinking to myself I should come back and complain, I hardly complain but he' seems to be a nice guy and said if you got any problems come visit us again. So yeah he did the PS Flush for 20 bucks more of a pocket-to-pocket transaction.

kevin444

So in conclusion im partially satisfied but should I even bother going back becuase of this soo called flush? I mean they did it this way with other cars and those cars showed no problems.

Cardesign

wow thats weird. I am sure that they are supposed to disconnect the cooler lines and run in through their machine to pump it all out. the basically did teh dilution method for you.

Wrenchmonster...what i was confused about was the part when you said to fill one bucket with the new atf. Does the return suck all the new atf out of the bucket? I thought you had to manually fill it.

kevin444

Im pretty sure you have to fill it. Unless its the other line going from the radiator than that might be the suction line.

wrenchmonster

Your AT has a pump inside that will pump the fluid all by itself. No need to run anything through the dipstick tube. The only thing I use that for is topping off to the correct level and re-checking after driving around.

Cardesign, that's why I mentioned placing both hoses into the empty bucket to start. That way you can observe which hose is pushing out the fluid. The hose not pushing out fluid is the "sucker" hose and will go into the new ATF.

Kevin444, sorry, but it sounds to me like your mechanic needs to buy a flush machine. The service I do at my work is a BG service. We start by putting in a cleaner and running your transmission (actually driving) and getting it to full temp. Then we tap into the cooler line and hook up the flush machine. The flush machine uses approximatly 16 quarts, yes I said 16. Then as the engine is running and the fluid is exchanging we run through the gears a few times to flush out the valve body. In this service nearly ALL of the old fluid is removed. I'd estimate a good 90-95% of old fluid gone. After we are done with the machine, a modifier is added which basically keeps the seals in good condition and keeps the clutch packs grabbing.

For the power steering, well the process EZ-LUBE did is pretty much the only way. The only difference is the shop I work in is that we do roughly 4-5 exchanges, not two. Again, we have a special machine, but the concept is exactly the same.

Kevin, I don't think EZ-LUBE did any harm, but I'm not sure how much good they did either. Particularly with the transmission flush. I'd look and find a shop that does "BG" services. This is by FAR the best preventative maintainence program out there. My 2 cents.

-Wrench

TechWrench

The return line from the radiator cooler to the transmission does not 'suck' the fluid back into the transmission. When both lines are connected to the radiator and the circuit is intact, the pressure line from the transmission forces the fluid through the radiator cooler and back to the transmission via the return line. If you open the circuit by disconnecting one of the lines, the return line is neutral, but the pressure side will still pump fluid when the transmission is running (engine running). So, in order to refill the transmission using the bucket method, you must add new fluid into the transmission via the fill tube. What one type of flush system uses is a bladder type of pump. The new fluid is in an enclosed part of a tank with a connection to the return line. Inside the tank is a bladder or diaphram which creates a second chamber inside the top of the tank which holds the old fluid coming from the pressure line from the trans. As the old fluid is pumped into the bladder, it forces the new fluid in the other half of the tank back into the transmission through the return line. Another type of system, uses an aux pump to push the new fluid back into the trans via the return line. And there is a third type of flushing system which connects directly to the trans valve body while the pan is removed and uses the main pump pickup in the filter input to feed new fluid into the trans and converter to force the old oil out. Each type has its pros and cons, depending on who you talk to.

wrenchmonster

Techwrench, you're right (and I'm showing my age). Now that I think about it.... sorry I was just going by what an old timer told me, but I've never actually done the bucket method as I'm lucky enough to have a proper machine at my disposal. Not to mention I don't own any automatics. My apologies to you Cardesign.

I wonder if you could get a seperate pump to force the new ATF back into the lines?

The BG machine I use at work uses such a bladder system, and also has a "booster" option which is essentially a pump to force the fluid back in. However, I've been told to stay away from the 'booster" as this might overpressurize the system? True?

Techwrench, I've never heard or seen of the 3rd flush you described where it hooks directly to the valve body. What would be the advantage of this sytem over the bladder type? Just curious.

-Wrench

kevin444

Should i even bother worrying about the change. Or should i just changed it like 10k miles or so.

dragon564

All the GEN2 came with ATF II which for the most part is no longer manufactured and it is getting harder and harder to come by. I called Toyota Japan about this and they told me that both Toyota Japan and U.S.A. had put out a notice to change all of the FSM to ATF III. The latest FSM for the GEN2 reflects this update.
CARDESIGN,

What they did is not a flush and they should not be calling it a flush they chaged the fluid by dilution, yes each time time the dump the pan the ratio of new ATF goes higher but it would take more than 3 runs at it to get all of the old ATF out of the new. The post from wrenchmonster lists 16 qts of fluid I do not have the book right handy but that "SOUNDS' right so try thier method with a bucket of water and some food color, only reduce to amout from qt to CUP. Start with a 20-25 cup bucket pour in 16 cups of water then add some food coloring and use enough to get a good depth of color I would use red and enough of it to make it look as dark as ATF. Take out 4 or 5 cups hold one aside for a based line and just add back in clear tap water stir it up and repeat two more times just as they did now take out a cup and compare it with the base line from above.....sure it is different but it is still a light red or pinkish color and not the clear tap you where putting in. IMO The method and machine that wrenchmonster speaks of is the best method

TechWrench

[QUOTE=wrenchmonster]Techwrench, you're right (and I'm showing my age).

OK, lets not get into the 'age' thing, I just might lose that one.......

"" Now that I think about it.... sorry I was just going by what an old timer told me, but I've never actually done the bucket method as I'm lucky enough to have a proper machine at my disposal. Not to mention I don't own any automatics. My apologies to you Cardesign.

I wonder if you could get a seperate pump to force the new ATF back into the lines?

The BG machine I use at work uses such a bladder system, and also has a "booster" option which is essentially a pump to force the fluid back in. However, I've been told to stay away from the 'booster" as this might overpressurize the system? True?""

I can't say for sure, because I haven't been able to study the circuit path of the A340 line, but from past experience with other types of transmissions, the return line is often used to provide lubrication to moving parts in the rear part of the unit. Some pressure is needed to provide the flow needed, but too much pressure would probably not be a good thing. I would guess that the cooling circuit uses between 10-15 psi, so if you stayed within that area it shouldn't be a problem.

""Techwrench, I've never heard or seen of the 3rd flush you described where it hooks directly to the valve body. What would be the advantage of this sytem over the bladder type? Just curious.""

I haven't actually seen one either, but other members (Gadget) have mentioned it. From what I can gather, this type of machine brings the new fluid into the trans directly into the pump pick-up line. This allows the new fluid to go directly to the torque converter which hold the largest amount of fluid in the trans. In most units, the fluid from the converter, where the heat is generated, is pumped into the 'out' cooling line to the radiator cooler. And, because the main pump also supplies the other circuits to the valve body and clutch packs, an exchange happens more directly there. In this manner, you have less mixing of the old fluid with the new, so it will probably use less fluid to do the complete flush.