Complete ATF Change...Best Way?

[paulo57509]

This is called a poor man's flush, and its the second best way.

The best way - IMHO - is a a poor man's flush with a helper - the helper starts the engine - you pour fluid down the dipstick at approximately the rate fluid is coming out into the bucket. The helper is there to stop if you get behind. You keep this up until the fluid coming out runs clear, button it back up, and add / delete fluid until your at the correct level.

However I agree that in most cases a drain and fill is sufficient.

Not to get too far off topic -

I've always wondered if you don't have a helper, is there any difference doing it this way:

1. Run the engine until 2-3 qts. is pumped out.
2. Stop the engine.
3. Fill new fluid thru the dipstick 2-3 qts.
4. Repeat 1-3 until fluid runs "clean".

 

[dlundblad]

I would do at least 3 drain and fills every weekend or when it’s convenient.

My brother in law and I did like 4-5 in one day. We’d just drive a few miles and that seemed like it was enough. It doesn’t take like to mix fluids.

 

[jhs914]

Getting close to time to change my ATF in the 8L45 in my GMC Canyon. What is the best way to swap as close to 100% of the fluid out without going to the dealer? A pan drop and filter change only gets about 50-60% of the fluid.

Once upon a time on an older vehicle I didn’t care too much about I hooked a clear hose to the outlet line that went to the radiator. I started the engine and at the first sign of air bubbles (trans pump had sucked the pan almost dry) I shut the engine off and added the same amount of fluid that got pumped out back into the transmission. I did this 3-4 times and 100% of the fluid was changed over to brand new stuff.

This still a good idea? Or an I just better off draining the fluid out of the pan a few times? Thanks!

Whatever you do be sure you use the Mobil 1 HP LV ATF in the blue bottle. Don't use Dexron VI.

 

[Stimp]

Not to get too far off topic -

I've always wondered if you don't have a helper, is there any difference doing it this way:

1. Run the engine until 2-3 qts. is pumped out.
2. Stop the engine.
3. Fill new fluid thru the dipstick 2-3 qts.
4. Repeat 1-3 until fluid runs "clean".

A lot of GMs you can pull the Jesus clip from the upper atf cooler line, pop it out, and push 3/8" OD poly tubing into the port. There's a seal that will keep it tight, then do the poor man's flush as described. Plenty of videos on YouTube. That's how I change the fluid on my 2011 Buick.

See around the 7min mark here:

 

[AdmiralYoda]

Whatever you do be sure you use the Mobil 1 HP LV ATF in the blue bottle. Don't use Dexron VI.

No way would I touch Dexron VI... Dexron HP only! I'm probably going to stick with Mobil 1 HP LV until the warranty is up and then its on to HPL's ATF Green Cold Climate!

 

[thescreensavers]

Not to get too far off topic -

I've always wondered if you don't have a helper, is there any difference doing it this way:

1. Run the engine until 2-3 qts. is pumped out.
2. Stop the engine.
3. Fill new fluid thru the dipstick 2-3 qts.
4. Repeat 1-3 until fluid runs "clean".

Nope, can do that no problem. Just easier with a helper.

 

[AdmiralYoda]

A lot of GMs you can pull the Jesus clip from the upper atf cooler line, pop it out, and push 3/8" OD poly tubing into the port. There's a seal that will keep it tight, then do the poor man's flush as described. Plenty of videos on YouTube. That's how I change the fluid on my 2011 Buick.

Amazes me that all that holds the transmission (and engine oil too) lines on is a cheap split-ring clip!!!!! Just ordered a set of the Jiffy Tite removal tool used in that video!!!

 

[chrlsful]

sit back & let a national use the completely closed vac machine and ck after w/fine toothed comb (fittings tight, right level, right oil, etc) or use one "@ home". I havea "bag", fits most transmis, remove pan/filter, attach to rolling waste oil tank under while on lift, spin tq converter, move thru gears (run abt 10 sec), follow standard re-fill sequence.