Drain transmission hot, or cold?

[addyguy]

I started this thread on Escape City about doing a 4-quart drain-and-fill on the tranny of my 2003 Tribute: http://www.escape-city.com/viewtopic.php?f=8&t=12794 As you can see, a poster indicated I would get more fluid out if the tranny is drained cold. My assumption was that, like engine oil, transmission fluid should be drained hot, so that more 'junk' comes out with the fluid, and it drains easier. Is it better to drain a transmission cold, or hot?

 

[Artem]

You won't get all the fluid out anyway. If you're doing a good flush, it will take 2-3x drain n fills. I personally do it every which way. Drain the first few quarts in the morning. Take it for a spin around the block, do another drain n fill. Take it for another spin on the highway and do a final drain.

 

[45ACP]

I say line flush her. Find where the "radiator ATF return line" is. Loosen nut. Take line off. Have somethin for it to drain into or its a mess BTDT. 1. Let whatever comes out drain. Note color and texture. 2. Start the car and let it run! You are getting a good flow of the fluid and a LOT will come out. 3. Watch when it starts to run dry, turn car off. Replace line and tighten it back up. Try to note how much came out, and color. 5. Replace about half what came out with fresh new fluid. Start her up.. and add the rest. Let it warm and even up, shift the shifter through all gears letting it stop 10-15 seconds in each one (seems unnecessary but you are seeking full flow, TC engaged, etc etc, reverse engaging, all the bands and clutches and "clutch packs") and check leve. Then drive it, see how it feels. get it GOOD AND HOT at this point. Then check again, and top off in half-quart increments to desired level. You can start this warm or hot its up to you.. If you can get it off hot using a glove then go for it since hot fluid flows easier.. Cold levels are inaccurate so perhaps start this procedure when it is "warm." Im not sure how you wouldnt get most all of the fluid with a line flush method. You dont want to run her completely DRY i dont think as one did with his car (put line back on put in ~4 quarts again let it sit a minute let it run again until it started to sputter) but thats debateable i suppose.

 

[bradepb]

I drain my escape when it is just warm,partly because i worry about the steel plug and aluminum case.I do it every 15000 miles or so. When i first got the car i did more frequent drains till i figured all the old fluid was out.

 

[sunfire]

Originally Posted By: addyguy

As you can see, a poster indicated I would get more fluid out if the tranny is drained cold.

If you don't allow the tranny to drain properly and you decide to remove and clean the pan. You will have a huge mess. The tranny will leak all over the place.

Originally Posted By: addyguy

My assumption was that, like engine oil, transmission fluid should be drained hot, so that more 'junk' comes out with the fluid, and it drains easier.

A cold engine will always get more oil out. The drawback is there could be more 'junk' that has had a chance to settle in the pan.

 

[LckydevL]

Originally Posted By: 45ACP

I say line flush her. Im not sure how you wouldnt get most all of the fluid with a line flush method. You dont want to run her completely DRY i dont think as one did with his car (put line back on put in ~4 quarts again let it sit a minute let it run again until it started to sputter) but thats debateable i suppose.

Just to add a few points to the excellent post above. Mark your "catch" container in quart increments. When you drain 4qts, turn off motor and put 4qts back in trans. Repeat this until fluid that comes out is cherry red and clear. Anytime I have done this, it usually takes capacity of trans plus half to get the fluid clear and bright red. In other words, if your trans holds 10 quarts. Buy 15qts and it should be enough to get the fluid looking good.