RegularGuy

So i picked up a factory ZJ trans cooler for a decent price in the junkyard. I've noticed its much beefier than the factory XJ one.

I'm assuming the most logical place to put it will be in front of the mechanical fan, which always runs. So this means that the cooler will be on the other side of the radiator from the lines into/out of the rad.

the reason i went ahead with the trans cooler was that i needed to replace a leaky return line from the tranny anyway. I'm wondering how much soft line i can get away with in this new routing- say i take the return line from the radiator, use a soft line to come around to the cooler, then a soft line from the cooler output, ,down to the passenger side of the radiator, then connect it to the hard return line to the transmission.

theoretically i could just target exactly where the line is leaking (seems to be right at the area between the front of the engine and the radiator), cut the hard line behind that, and then clamp the cooler output line to there.

Is this a decent idea i can draw up a diagram if that helps.

RegularGuy

Here is the cooler.Seems in decent shape.

Here is what I'm thinking of doing.
The red and blue are the send and return lines. the purple section is where i suspect the leak is. On the second diagram the green lines are what I'm thinking of routing with rubber hose.

thoughts?

bad_idea

That is exactly what I did. The issue you will have is the cut end of the tubing doesn't have a barb on it. I put two hose clamps on the connection, but the hose is working it's way off the line slowly. I plan to buy some of these: https://www.summitracing.com/int/parts/rnb-800-036. IIRC the lines are 5/16, if not buy the right size.

Keep the rubber lines tucked up out of the way of ob-stacles. Protect the hoses from chaffing at any points they contact the chassis.

RegularGuy

Maybe i'll get a rubber hose sheath or protector or whatever its called for it.
Maybe i'd also be better off going back to the junkyard and pulling the hard line from the ZJ that was the output from the radiator and went around to the front for the input of the cooler. I'd have to add some rubber line to place the cooler where id want it but it wouldnt be as much rubber as running the whole section that way.

I do know i should use a spinning pipe cutter to cut the hard line, so it doesnt leave shrapnel to get washed into my transmission.

fijicorey25

I have the ZJ cooler on mine. I put it on the passenger side of the radiator. I didn't need any additional hard lines, just some rubber lines spliced AFTER the internal radiator cooler. I used this to secure it in place. It seems fine:




I can get some pics after I'm done working today, let me know.

BlueRidgeMark

You can run 100% rubber line. It's not a problem at all. It's not as clean and neat, but functionally, it's just fine.

You can also buy some cupro-nickel line and bend it by hand, or with one of the cheap benders they sell at the auto parts store. That stuff is a dream to work with.

You want the trans cooler in front of your radiator.

RegularGuy

Pics of your cooler install would be nice, Corey!

I may install it this weekend when i can scratch together enough money for all the tranny fluid i'll need. I still want the flow into the cooler on the bottom, and the output on the top, right?

fijicorey25

Here's a couple of pics before I got everything cleaned up. I have the inlet on the bottom and the outlet on top. I ran the hoses through a hole that's in the front bumper right behind the grille. I only had to cut and splice my existing trans lines which are in good shape. I didn't lose too much fluid nor did I need to add a lot extra.

IJM

Yup. That way you won't have issues with trapped air.

RegularGuy

Well now i think im going to need to install some shift solenoids into the tranny so even more of an excuse to squeze this in i guess.

Might not be the easiest to pinpoint exactly where the leak in the return line is though

Another reason to have the input on the bottom of the cooler is so that the fluid dwells longer in the cooler, making it more efficient, correct?

bad_idea

You fill from the bottom up to displace the air. Filling from the top down you may end up with air pockets.

TRCM

If you are worried about the hose coming off the line with no barb, put a small flare on the end of the line...

or if ya have a welder, you can put some bumps on the line as well for the hose to slide over

or you can weld a clip on the line above where the clamp goes, and put the clamp over the clip as well as the hose