Trans flush question

[Dekeman]

Hi all,

I'm going to do the transmission flush and I'm not sure of some things:
- Where is the line off the cooler where you drain it from? I know the manual procedure for the flush has you disconnect the cooler at the radiator, but Wiswind's pics look different than that.
- Some folks have mentioned that you're supposed to let the pump cavitate before you turn off the engine while flushing. The manual says to turn it off after it stops flowing (only 2-3 quarts) so as not to cause damage. That's certainly not going to get all of the fluid out of the pan. I was wondering if I could do this in the driveway and drop the pan/wipe the pan and magnet/change the filter, but the mess of dropping the pan with fluid in it makes me leery of getting my driveway stained (I'm renting the house).

A possibility is to use a fluid pump down the dipstick tube to drain a lot of fluid out before dropping the pan. If I do that, I imagine I shouldn't disconnect the tubing for the flush until the pan's back on and the trans is overfilled by a few quarts.

[12Ounce]

There's no one absolute right procedure. Kinda like religions.

I prefer to:
(1) Start by "draining" through hose until flows lessens (pump is cavitating now). Shut down engine right-away .... best to have helper.
(2) Now I drop the pan, swab out ... replace filter etc, etc.
(3) Now overfill the tranny with fresh fluid ... perhaps 8 qts or so. Restart engine and continue draining until pump cavitates OR stream cleans up. Again shut down engine right-away. Repeat until waste stream is clean.
(4)Rehook hose .... and top-off properly.

Usually takes me 12 - 14 qts of fresh fluid.

[tempfixit]

Originally Posted by 12Ounce

There's no one absolute right procedure. Kinda like religions.

I prefer to:
(1) Start by "draining" through hose until flows lessens (pump is cavitating now). Shut down engine right-away .... best to have helper.
(2) Now I drop the pan, swab out ... replace filter etc, etc.
(3) Now overfill the tranny with fresh fluid ... perhaps 8 qts or so. Restart engine and continue draining until pump cavitates OR stream cleans up. Again shut down engine right-away. Repeat until waste stream is clean.
(4)Rehook hose .... and top-off properly.

Usually takes me 12 - 14 qts of fresh fluid.

I have done like 12Ounce says only adding a lenght of hose to the 1 removed from cooler so you can drain into gallon milk jugs, etc. Also have placed large cardboard boxes under vehicle to eliminate spillage onto driveway.

[Dekeman]

Awesome- thanks guys. Does cavitating the pump empty the pan, or is there a lot left in it when you drop it?

[12Ounce]

I also use the hose "extender" ... good point!

About one pint, maybe more, is left in pan after the pump cavitates.

[Dekeman]

Originally Posted by 12Ounce

About one pint, maybe more, is left in pan after the pump cavitates.

SWEET!! Just what I wanted to hear. Thanks!

[12Ounce]

Perhaps I should have guessed a "quart". Enough left to make a mess for sure.

I always lay out a tarp, and drive on top of it, for this operation.

[tempfixit]

When I take the pan off I go the store and get the largest aluminium turkey cooking pan I can find. Then I remove all the pan bolts except for 1 corner then I use a screwdriver and pry 1 corner down a little to drain the pan until fluid stops then remove rest of the bolts. There should be very little left in pan at this point.

[Dekeman]

Cool, cool- good idea with the tarp.

Last question- promise! Where do I take off the cooler line? At the radiator or at the trans? That plastic fastener doohickey looks either complicated, or easy to break, or both.

[12Ounce]

I remove the line from tranny (Upper, IIRC) ... the plastic retainer is rather easy to release ... "once you've done it".

.... but at the moment, I haven't a clue how it works!! Hope it "comes back to me" when I next try it! I believe gently squeezing it radially while moving tubing in-and-out will release it. Hope so.

[olopezm]

Originally Posted by 12Ounce

I remove the line from tranny (Upper, IIRC) ... the plastic retainer is rather easy to release ... "once you've done it".

.... but at the moment, I haven't a clue how it works!! Hope it "comes back to me" when I next try it! I believe gently squeezing it radially while moving tubing in-and-out will release it. Hope so.

Unless somebody else advises, I think the correct hose that needs to be dettached is the lower one, at least that's what I can remember from reading other posts.

Oscar.

[wiswind]

YES the factory instructions say to remove the metal line from the tranny or the radiator.
I always did the hose, because I was afraid that I would mess up the quick release connector, and/or not get it back on "just right".

Stop flowing / cavitate.......
Cavitate is when it is drawing up air from the pan......so I like to stop at that point, or, if the flow stops.
The difference between the two in amount of fluid pumped out is not a lot, but I don't want to have foam in the system or run the tranny without sufficient fluid for any length of time.
The sufficient fluid is my concern, so I would stop when it starts pumping bubbles OR stops flowing fluid out....whichever comes first.

Once you get some cavitation.....the very first fluid to come out the next cycle.....after you have added more new fluid and started the motor back up.......will have some bubbles in it....but not for long.

I like to use a length of clear hose......large enough to slip over the cooler hose that I disconnected, so that I can easily see the fluid flow through it.

The total amount of fluid in the transmission and cooler is 12.25 quarts.

Kudos to you.......changing out the tranny fluid is a super good thing.

[12Ounce]

Thanks guys, you beat me back to the keyboard with the correction ... the more I thought about it, I realized it is the LOWER hose/tube fitting at the front of the tranny. (Old geezer!)

I think you should give that quick-disconnect a try next time. (Even though I can't remember at the moment how it works.) It is an o-ring seal and pretty sound. Remember the fluid pressures are not that great in the cooler system.

[09stang]

Also use gloves and long sleve shirt. That fluid made me sick when a bunch of it got on my arms when dropping the pan. Had nasty headache for few hours. Maybe it's just me?

[Dekeman]

Originally Posted by 09stang

Also use gloves and long sleve shirt. That fluid made me sick when a bunch of it got on my arms when dropping the pan. Had nasty headache for few hours. Maybe it's just me?

That is really nasty stuff! I've had my van on a lift the last two times I've done the pan drop/filter change, and a large catch container right under it, so the mess was minimized. Long sleeves are a must!