bradleyheathhays

'96 XJ here and I've added a trans cooler up front but haven't tied the lines in yet. When I go to splice these into the return line of the trans I'd like to do something of a fluid flush at the same time. After I split the return line I believe the flushing process involves letting some fluid pump out then stopping everything, filling up with new fluid, then repeating the process until what's coming out is fresh red fluid. Couple questions...

1- How much fluid should I let pump out at a time before refilling? 2qts, 3qts?

2- What starts the trans fluid pump to pumping? Is it when the engine starts or when it's put in gear? I'm just wondering what I need to do to start and stop the trans fluid flow.

and

3- What's a good transmission additive/cleaner to add to my trans before doing the flush?

joeyjeepz

This is what i have found , but the second one is for a trailblazer, hope this helps

cruiser54

Just fill it with fluid and drive it.

Do a few drain and fills.

nujeepguy

thats what im doing ,waste a little,,,ive done the pumpout on other cars but not in the mood, too cold!!
sucessive aproximation! eventually you are 99 %!!

DFlintstone

Like Cruiser says, just draining (what drains) and filling works. I like the suggestion of just "upping" the interval and doing it with oil changes till the fluid looks good. Btw it just has a screen, not a filter. The screen is fine unless something really went wrong.

Since you have the line off already you might let it idle until the flow drops, cut the engine and go from there. You will have drained more than will drain from the drain plug.

BlueRidgeMark

Hmmm. I see something up there that looks familiar.

Don't worry about any additives. Just clean Dex/Merc.

TJ805

I like the drain and fill technique, but I think the previous owner of our new 2001 XJ used atf or gear oil. It's the one that smells REALLY bad. I'll probably flush it, but would also like to know more about the stinky oil. What is it? Is it safe to use? Is it compatible with Mercon? IS it Mercon? Any help is always appreciated.
-TJ

TJ805

I like the drain and fill technique, but I think the previous owner of our new 2001 XJ used atf or gear oil. It's the one that smells REALLY bad. I'll probably flush it, but would also like to know more about the stinky oil. What is it? Is it safe to use? Is it compatible with Mercon? IS it Mercon? Any help is always appreciated.
-TJ

Sorry for the double post.

Red1992XJ

Drain and fills are honestly a little easier. I would rather open and close a drain plug a few times than cut a steel line and give another spot that could leak. Walmart sells the dex/merc for like 15 bucks a gallon, which should be more than enough to replace what you drain out. Do that a few times (4 or 5) and you should be pretty cleaned out, then do it every 30000 miles. Trans should work just fine (assuming there are no other underlying problems.

BlueRidgeMark

Make it simple. Dex/Merc Dex/Merc Dex/Merc

Don't mess with anything else. Don't try to improve on it. Dex/Merc Dex/Merc Dex/Merc

Here are the instructions for a complete flush, as provided by a retired Ford transmission engineer, Mark Kovalsky. Yes, it's for a Ford, but the steps are almost the same. The only difference is, the AW4 has no real filter, so there's no real reason to drop the pan,. Just do the flush.

https://www.ford-trucks.com/forums/1...and-video.html


And no, you won't "shock" your transmission. They have been around the block a few times, they have seen things that would make a sailor blush. They don't shock easily.

cruiser54

Just in case nobody has mentioned it........

BlueRidgeMark

Cruiser, are you saying he should stick to Dex/Merc?

(I think he's saying you should stick to Dex/Merc.)

cruiser54

Just a thought........