Transmission flush?

R

Rangeroad

New member
Hi all,

My first post, I just picked up a 4cly 3RZ-FE in really good shape but getting close to 150k. What is the general consensus of a transmission fluid flush from a reputable garage? I've heard after high mileage that you should just change the fluid and stay away from the flush. The PO was good with his servicing, but only changed the fluid once prior and did not do the flush.

Cheers!
 
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Flush is risky, many older tranny's have failed following a flush. Drain and fill once a week for a few weekends and you'll have new fluid in the tranny, and no risk of failure.
 
My personal opinion is at this point, assuming the fluid is still bright red and doesn't smell burnt, a regular schedule of drain and fills should keep the tranny healthy for a long time. First time it would be a good idea to drop the pan, in doing you can take a look at and clean the magnets and also replace the filter. You could clean the filter, just a mesh screen, and reuse, but for $20 or so you can get a kit at most parts stores, not Toyota, which will include a new filter and rubber gasket. Well worth it to avoid the annoyance of scraping off all the old RTV sealant everytime. This way you can do all the work yourself saving some cash, and also know it's done right.

On the issue of a flush it seems the newer techniques utilize the vehicles own pump to cycle the fluid, at first the machines had their own pumps which seem to have pushed a higher pressure, thus leading to failures, or so was the theory, sludge or such being moved where it shouldn't clogging up the works. If the machine does not introduce any pressure above what is normal I don't see how it could do any harm, and you have the benefit of replacing all the fluid at once and forgetting it for 30k, so I suppose if you're not doing the work either way this could be more economical. And then again you could research a bit and do a full flush yourself in the driveway.

Personally I have subscribed to the regular drain and fills with the occasional pan drop. Seems to be working fine as my fluid always looks brand new and the tranny shifts great at 140k.
 
Seafoam makes a "trans flush" product that we use with pretty good results in our service department. I don't have any experience with it myself, but we keep it in stock for trans flushes, so I can't imagine it is causing any harm. We do lots of trans flushes on older high mileage Chevrolets and Mazda and I don't see us rebuilding a whole lot of transmissions.
 
Had mine flushed at 216k miles. Now at just over 235k and two years later w/ no issue's.

Good luck whichever route you take.
 
What I did, and worked great:

- Drain fluid that's currently in the tranny pan.
- Drop the pan
- Clean magnets well, and wipe out pan
- Replace filter and pan gasket (I used a rubber gasket to replace the RTV gasket that was there, but some more RTV will work fine).
- Mount new filter and bolt pan back up.
- Fill with new tranny fluid through the dipstick (with a funnel) until full (I used Amsoil Synthetic).

Here's the part that you'll need another buddy to start and turn off the car:
- Located at the very bottom of the radiator, you'll find a fitting with a clamp on the driver side.
- With the engine OFF, pull this hose off and let any free transmission fluid drain into a bucket.
- Now grab an EMPTY quart bottle of radiator fluid, and place another rubber hose from the metal fitting, into the empty bottle (the fluid will come from the radiator, not the hose you removed).
- Have your friend start the engine, and once it get's about 3/4 full in the quart bottle, yell at your friend to shut it off.
- Once the bottle stops filling, dump it into the bucket.
- Pour a quart of new fluid back in through the dipstick (with a funnel) to replenish what you removed.
- Keep doing this until all of the old fluid is "flushed" out of the system, and you see new fluid coming through.

The reason why flushing is seen as being bad, is because it causes the fluid to flow in a REVERSE motion, pushing all of the containments in your filter out and into the tranny.

This method of "flushing" lets the fluid flow naturally, without any force, and will remove all of the old fluid properly.
Draining and filling. Draining and filling, just wont get all of the old fluid out. You're just mixing new with old, and albeit it does help, you're also draining new fluid out every time you drain it. Waste of money, and you won't ever be able to get all new fluid in there.
 
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disconnect the return line, and fill from the dipstick, should get most of it out. Look around there is a DIY for this method. Prob linked in my thread as I did it this way.
 
I would take it to a T-Tech machine myself, it does a full drain and replace without "flushing" it.
It just uses the pump in the 4Runner acting just like it does normally and exchanges good fluid for used.

IMO doing a "drain & fill" is basically just like peeing in the ocean.
draining out 3-4 Qts then mixing good fluid with about 10 or more of used fluid is worthless.
 
bootown said:
Your "10 or more" is wrong (actually it's closer to 7 or less) and analogy is so far from the truth (I'm sure you were just trying to make a point though). A single drain and fill results in removing 35-40% of the old fluid. After 4 d&f's you are left with about 15% old. Far from worthless except for the super :moon:
Click to expand...

True I was thinking what was required to actually do it which is a couple+ Qts more than what it actually holds.
But it is still about 11Qts to fill and you get at most 4 Qts out if you are lucky.

No matter what you are mixing good clean fluid with crap that mixes together.

Would you drain just 2Qts of engine oil out and replace 2Qts at a time and call it a good deal?
Same difference to me, so I consider mixing 3-4 Qts of good ATF into 7 of used ATF as pretty much worthless.
Especially when you can just take it to a T-Tech machine or do what 004Runner stated and actually "Change" the fluid.
 
running a QT's of ATf through the transmission is essentially the same thing as doing a flush right, never ever do a "power" flush on ANY vehicle over 50-60k if it hasn't been done before, the power flush is any machine that they hook up to your truck and pump fluid through at high pressures to clean it out, this is not good on high mile trucks as it'll break things lose and clog your valve body filters and channels.

beyond that there is no difference in most of the methods mentioned here, if you go to a good shop they will simply cycle atf through the transmission using the trans pump already in your vehicle, this is exactly that same thing as people doing the drain and fill technique, they are both doing the same exact thing it's just a matter of how much time and effort you want to put into it.

whatever you do, do not allow any shop to use a high power flush machine on your truck, ever, this is a different story though on a truck that has 20-30k on it and you routinely do the power flushes, that's fine, it's when you got lots of miles and do the power flush you screw things up.
either way you decide to go i'm sure it'll be fine.
 
Ya know, I've been wondering this myself.. My '99 LTD has 252k miles on it, and I have NO idea if the trans has ever been serviced. I thought about doing the pan drop, new filter, and then draining through the cooler hose until it is completely swapped for new fluid, at the same time I do my external cooler mod... But the mileage scares me a bit...
 
Thinking about doing this the way 004runnerLtd wrote about. Does anybody know the size of hose to use on the metal fitting from the radiator when filling up the quart bottles of old fluid? (inside/outside width). I realize I could figure it out once I get it off but trying to get everything I need all at once.
 
004runnerLtd said:
What I did, and worked great:

- Drain fluid that's currently in the tranny pan.
- Drop the pan
- Clean magnets well, and wipe out pan
- Replace filter and pan gasket (I used a rubber gasket to replace the RTV gasket that was there, but some more RTV will work fine).
- Mount new filter and bolt pan back up.
- Fill with new tranny fluid through the dipstick (with a funnel) until full (I used Amsoil Synthetic).

Here's the part that you'll need another buddy to start and turn off the car:
- Located at the very bottom of the radiator, you'll find a fitting with a clamp on the driver side.
- With the engine OFF, pull this hose off and let any free transmission fluid drain into a bucket.
- Now grab an EMPTY quart bottle of radiator fluid, and place another rubber hose from the metal fitting, into the empty bottle (the fluid will come from the radiator, not the hose you removed).
- Have your friend start the engine, and once it get's about 3/4 full in the quart bottle, yell at your friend to shut it off.
- Once the bottle stops filling, dump it into the bucket.
- Pour a quart of new fluid back in through the dipstick (with a funnel) to replenish what you removed.
- Keep doing this until all of the old fluid is "flushed" out of the system, and you see new fluid coming through.

The reason why flushing is seen as being bad, is because it causes the fluid to flow in a REVERSE motion, pushing all of the containments in your filter out and into the tranny.

This method of "flushing" lets the fluid flow naturally, without any force, and will remove all of the old fluid properly.
Draining and filling. Draining and filling, just wont get all of the old fluid out. You're just mixing new with old, and albeit it does help, you're also draining new fluid out every time you drain it. Waste of money, and you won't ever be able to get all new fluid in there.
Click to expand...

IMHO this is the best advise you will get on this subject, it works and is low risk.
 
hey man, flushed the tranny on my '99 4CYL today and only ended up using 8 or 9 QTS. Used Valvoline DEX/MERC high mileage. Paid no attention to the filter. Shifts like buuuutter. ;)
 
Sounds great. Only info I need is what size hose is needed to drain the fluid from the radiator. The info on how to do it is very helpful, just missing that one piece of info.
 
And here's another Trans Flush Video for your viewing pleasure:

<iframe width="560" height="315" src="https://www.youtube.com/embed/RumPXivBlk8" frameborder="0" allowfullscreen></iframe>
 
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