Transmission flush (fully 12 qt) 6 steps!
After replacing the transmission cooler lines, clamps, hose stabilizer bracket and making sure I've no leaks. Flushing was final PM service for transmission. I did add ~1 qt of M1 MV ATF and drove for awhile, to watch for leaks. I saw no leaks. So I assume it was low due to either not fully topping at last flush (history showed a 12qt flush at 395Km, and 4 qt D&F at 219Km) the cooler hose leak/weeps or a little of both.
I like to do full 12 qt flush with synthetic ATF. History showed it had been done before, fluid looked and smelt okay. So I was not overly concerned with fresh Mobil 1 full synthetic ATF, cleaning gunk from clutch plates. My feeling on transmission is; If so bad that a good cleaning by new ATF destroys the transmission, it's going to fail anyway. May as well be while in PM and inspection faze, and not 200 miles from nowhere. If I'm overly concerned, I may do a ~3qt drain and fills (D&F) a few times, over a few hundred miles. It's believed these D&Fs, are easier on clutch plates and doesn't remove gunk that holds them together or gunk releasing clogging valves.
The older transmission with dipstick are so easy to flush. Why Toyota removed them in 04, well we've many opinions on that.
Procedure:
Step 1) First in any flush is to drain the pan which I'll get ~3 qts., depending on how long I let it drain. The A/T Pan is where fluid is first picked up from pick up tube and starts it circulating journey through the transmission and cooler lines. Once pan drained, I then torque back in the drain plug, to 15ft-lbf with new washer/gasket.
Step 2) Next I disconnect transmission cooler return hose from A/T oil cooler out pipe. The last easily accessible point, before ATF flow going back to transmission. I attach a clear ~3/8" ID hose to pipe (upper), that the return hose was connected to. Run my clear hose, to catch can, which I've mark with 1qt interval line.
The return hose & pipe, are on PS of radiator, within engine bay. We've two hose attached here in the 98-02 models. (03-up has power steering hose in area also, but the same two transmission cooler hose seen in all years). I place a rag under my work area, and just let disconnected hose lay on it.
Tip:
a) To free hose (any hose) from hard pipe, which hard pipe is easily crushed. I move clamp back down hose, then genitally & slightly twist back and forth (rock hose clockwise and counterclockwise, just a little to free from pipe) the hose on pipe, with pair of channel-locks. Being very careful, to not squeeze hard with channel-locks pliers.
*Note of caution:
The now disconnected rubber hose from oil cooler out pipe. Is attached on other end, to return hard line going back to transmission. In one instance, someone had mixed up hoses. I lost ~1/2qt on the shop floor, before spotting fluid pump out return hose. So nowadays, if no flow seen through clear hose to catch can, within ~3 seconds of starting engine. I'll stop engine and I double check, that no flow from end of rubber return hose.
Step 3) Next is to remove dipstick and place transmission funnel in its place. Then add back the same amount of new ATF as was just drained from pan. It is fine to overfill pan at this point, if you like. I do overfill by about ~1/2qt, which helps me keep up with A/T as it pumps ATF out.
3-a)
Alternate A/T fill method:
The disconnect return hose from A/T oil cooler out. Can be use to fill A/T. It is where fluid exchange machine, out flow hose is connected. This is handy point to top 04-up, which do not have dipstick.
I marking catch can with quart lines, to tack how much ATF removed. This is so I/we know, how much is pump out as we proceed. We're shooting for a total 12 qts drained from pan and pumped out. Removing more gets wasteful. My first time I went through 18 qt at $12 a qt.. that was 6 ($72) wasted.
Step 4) Now we are set. Just need to start engine and let it idle. As it idles, ATF pumps out old fluid as we're adding new ATF fluid at same time. Helper is great here, to start and stop engine as I pour in new. But I generally do job alone, run back to driver set shut engine off. Either way, we do not what to empty the pan and suck in air. So keep eye on how much is coming out, and keep up with that amount by filling. By add more engine off, to keep pan full. Our only real concern here is letting pan run dry, So don't!
Tip:
As I get near 10 qts. out. I'll dump catch can and watch color of fluid closely. At 12 qts removed, I should see color become lighter (in clear hose and bucket). As new fresh fluid stars to pump out. I hold back about 1/2 qts, of the 12 qts of new ATF using to fill, for topping later. Since easier, to add dipstick (98-03), than remove any, if overfilled.
Be alert to level, watch level in catch bucket as you add. Stop engine as catch can start to fill more than amount your adding back in A/T.
This, as you can see, was last of 12 qts, out, which is clear.
Step 6) Is setting level. Once 12 qts out and ~11 1/2qts in. I remove my clear catch hose. Reconnect return hose to oil cooler out hard pipe. Bring A/T #1 up to normal operating temp of 158F to 176F and top. I nail the High line of hot on dipstick.
Remember vehicle/transmission must be level, checked while engine idling in park or N after shifting through all gears.
I use a OBDIImx w/iphone or Tech Stream to watch A/T #1 temp. OR shoot A/T pan with IR temp gun, on bottom center of A/T pan.
Note: A/T fluid temp #2, is only seen in 06-07, it is not used for setting level
Tip:
To bring A/T #1 temp up to target of ~160F. I do, by holding brake on, engine running, while shift through D-3-2-1-1-2-3-D, holding in each gear for ~30 seconds, with RPM raised to ~1,500. This loads A/T, slipping clutch plates creating heat. But, Do NOT load A/T in R. You can also drive to bring up temp.
I like Mobil1 full synthetic MV ATF in 98-02. I set level dead on full hot line on dipstick. Then check periodically to see if level drops, which would indicate a leak. No leak then level will always be same, at same ATF #1 temperature. As mentioned: You can shoot transmission pan with IR gun and get a close reading of temp of ATF. But, make sure IR gun within 3 inches of pan. In my shop, with concert floor at 78F. My IR gun reads about 3F less than ATF #1 temp as read through tech stream.
I had also pulled inspection plate from bell-housing. Just looking at condition of flex plate starter gear teeth or cracks, etc and for any signs of leaks. After all it has over 350K miles, can't hurt to look, right! But not part of a flush.
BTW: Most all fluids from Toyota are from Exxon Mobil.
