On the AW4 tranny, hot tranny fluid exits the front metal line passenger side, enters the rad cooler at the bottom drivers side, exits the top of the rad cooler and returns to the tranny via the rear metal line passenger side. For max fluid cooling, the auxiliary cooler should be spliced into the line returning to the tranny, which is the top fluid line in the rad cooler drivers side.

 

See what I mean, we resolved on my 2001 the feed line is at the bottom of the radiator and the instructions state to hook it in series to the return. The above post has it in series to the bottom. I am beginning to think it doesn't make any difference. Nice install by the way, is your bottom line the feed or return and where does it come out of the tranny front or back.

 

On the AW4 tranny, hot tranny fluid exits the front metal line passenger side, enters the rad cooler at the bottom drivers side, exits the top of the rad cooler and returns to the tranny via the rear metal line passenger side. For max fluid cooling, the auxiliary cooler should be spliced into the line returning to the tranny, which is the top fluid line in the rad cooler drivers side.
__________________
Man Law - hoods should be raised at least once a week....have a look.

Thank you, I am using the top fluid line.

 

Might want to re-read my post.....the return line (cooled fluid) is attached to the top of the rad and rear of the tranny.....that's the line u want to splice the auxiliary cooler into.

 

Got it thanks, was just commenting on the earlier picture post and how it didn't follow with what you had posted and my install instructions. Hopefully his lines were *** backwards or the instructions were different. My install instructions are generic and picture the hoses attaching to the return line on the bottom of the radiator which is wrong per your post and confusing at least.

 

I'm not too sure about what is said in post #15 but on our '98 XJ, the factory return/cooled line, going back to the tranny, is the line that connects to the top rad cooler nipple and this is the line we installed/spliced the auxiliary cooler into. This way, fluid is cooled 1st in the factory rad cooler, then cooled a 2nd time in the auxiliary cooler.....just like the factory plumbs their auxiliary cooler in their trailer tow pkg.

 

For the record, I installed mine by bypassing the radiator altogether. The feed line (front of tranny) is feeding the top of my cooler.

 

......which is the opposite of the factory set-up.

 

I didn't want it trying to push fluid up through the cooler. Haven't had any issues yet. If I ever decide to put the radiator back into the loop, I'll add it in series before the B&M.

 

Pushing fluid up is how the cooler is supposed to work..

 

.....and pushing air down makes foamy bubbles 'cause it wants to rise.

 

Fluid cavitation = bad

 

Ahh. Glad I said something. I must have missed that. I will make it a point to switch those lines. Thanks!