First of all, sorry about the long post. So I couldnt find any info on doing a complete trans flush, but if you guys know of a forum about that, feel free to share. Anyways, I was driving down a local stream for about 1/10 of a mile or so a few days ago and then drove home (only about a minute at 25mph). Once I got home, I checked all my fluids and my trans fluid level is really high and milky. I have a 1999 XJ with a auto trans and the water got to the bottom of my doors at the deepest. What would be the best way to do a complete flush on it? I heard that draining it only gets rid of less than 1/2 of the fluid in it. Should I just keep filling it up with fluid and draining it multiple times so that the water gets flushed out eventualy? Also, the previous owner told me that there was a extended breather hose on it, but it's nowhere in sight. I think it either never had one, or somehow fell off. Where and how would I attach a breather hose to it? Again, I couldnt really find anything online about it.

Just do a few drain and fill up.. Then you should be good to go.

vet hose should be located on top of transmission.

Pic for reference

Thanks for the reply. My friend likes to act like he knows everything about everything so he told me that I would need a whole new transmission but I didn't believe him so I figured I'd post it on here

LOL,, Yes a few drains will be fine.

Also dont let your friend tell you to change the filer..its a metal screen,, no filter media to get wet and hold water.

I'm coming close to 200k miles and the fluid is looking pretty bad so I might go ahead and change the filter while I'm at it

No need to..its a waste of time..unless you are dropping the pan to do gasket or solenoids.




The aw4 filters job is to keep large stuff out..not filter stuff out like a fuel or oil filter does.

Its just a screen, but theres no harm in replacing it. Just dont overtighten anything.

Yeah there is no harm,,but why?? its not damaged.

This is from the FSM (factory service manual) Number 2 in this step is the only place Ive seen it mentioned about cleaning the trans screen..

Even then it doesn't say replace the screen,,it says clean in solvent and blast dry with compressed air.

normally i would be right with you, EXCEPT...I recently drained my AW4, then poured the contents into bottles via a funnel with very fine screen, (like the AW4 filter)
the waste trans oil ended up plugging the screen, such that it almost blocked flow completely. I cleaned and examined this sludge. It suprised me to see this happen.

In addition, dropping the pan flushes 5 litres out, and a pan gasket & filter is like $10...if you can drop the pan without disconnecting exhaust, I would

I drained 4 litres by parking nose down, and start engine, cycle trans for a couple of secs while draining

takes 8 litres for a complete refill

to drain & flush to +90% takes about 15litres

Pouring the used fluid into a bottle with a very fine screen (like the aw4) is not going to prove anything about the filter needing to be changed . It proves the fluid was junk.
Did you have pressure behind it Like the aw4 would pumping fluid around.

Meh! if ppl want to change the filter cool..they can,, Ive done it many times when ppl ask for the filter changed. Ive shown them the used one before a cleaning and the new one.. All the looks I get are,, well fun..lol

Myself I think waste of money and time unless im doing the gasket or solenoids..

Complete fluid change made easy:
1) Drain old fluid, change filter, refill as per normal. This might be a good time to weld on a pan drain plug. Don't start the vehicle yet
2) Remove Tranny hose at radiator (this is a little difficult with these Jeeps, but remove the one easiest line)
3) Add a 18" length of hose (preferrably clear) on each end of the cooling line you removed (the hose AND the radiator side)
4) Put each hose into a bucket under your engine compartment (2 gal or larger with tall sides).
5) Add 1.5 - 2 qt more ATF fluid into the trans. You want to slightly overfill it.
6) Have a helper start the vehicle and watch CAREFULLY the ATF as it is pumped into the bucket. You need a helper for this job.
....It comes out FAST so keep an eye on it. Clear hose is helpful. Fluid will rush out of only one line. Only allow it to idle.
7) Basically run the vehicle until the fluid runs CLEAR (new) and shut vehicle off
8) It takes about 10-14 seconds to pump the old fluid out of the torque converter. Everything happens quick. ~1 gal will come out.
....You may need/want to stop the vehicle half way, add another 2 more qts and start again.
9) Re-connect lines and fill trans to the normal level.

Bingo - You just did a COMPLETE transmission fluid change!!! This is a common way to do it

Note: You really only need one hose into the bucket if you know which line is the 'supply' line. But rather than figure that out, just put a hose onto each end of the line you removed (radiator side & hose you disconnected), and ONE of them will supply fluid. Don't let old fluid 'suck' back in. If your fluid was old looking, you will notice the new (clear) fluid easily when you see it (unless you're color blind)

The trans already has a drain plug........and for good reason.

save yourself some probable aggravation and don't go near the filter.. just drain and fill or flush.