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Transmission Cooler Line

XJ_NorCal

NAXJA Forum User
Location
Patterson, CA
1998 Jeep Cherokee Sport
113K miles
I6 4.0 litre
AW4 Automatic Transmission
NP231 Transfer Case


One of my transmission cooler lines is leaking. It's the one that connects to the bottom of the Driver-side of the radiator (There seems to be confusion if it is the inlet or outlet). I'll be replacing the entire line. Should I replace the other cooler line at the same time? Are there any tips I should know that will make the install easier?

I've already been warned about the quick disconnect fitting. I've got the right tools to take care of that. All my searches bring up tranny cooler replacement and radiator replacement. I haven't found a specific cooler line replacement thread. Thanks NAXJA!
 
I personally wouldn't change a non leaking factory line with a newly made OEM line

They suck -- Doesn't matter if it's original factory equipment or not -- if it's not made 20 years ago it will leak in 6 months -- the new lines are terrible -- doesn't matter who made it

Me, I'd change it to -6an braided hose and never replace it again
 
The Dorman lines are garbage. The dealer lines were still available as of 6 months ago. I don't know if they are still available. I would get a dealer line or try something different. Consider getting a new quick disconnect for the transmission. Those you can get for about $8 at O'Reilly's, etc. It is typically the line that goes to the radiator that leaks, by the steering box. I don't see any reason to change both.
 
One of the first things I did to my Jeep, bought it kinda running but not driveable, was a radiator and replaced that lower line. Used a Napa one which I am pretty sure is just a rebranded Dorman one. Over 3 years later and it is still OK.
 
The bottom line is the inlet to the cooler, and the top is the outlet. It's arranged that way so you don't trap air in the cooler. Worse case just cut the fitting off and hose clamp some fresh hose onto the leaking section. There's little to no pressure on that line as it runs through the cooler and then dumps into the pan.
 
One of the first things I did to my Jeep, bought it kinda running but not driveable, was a radiator and replaced that lower line. Used a Napa one which I am pretty sure is just a rebranded Dorman one. Over 3 years later and it is still OK.

Was the replacement as straight forward as it seems?

The PO gave me the replacement line when I bought the Jeep. I've started chasing leaks and am just getting around to replacing it. It's from NAPA. I'm thinking I'll put it in now and research the new fittings and braided hose for whenever it starts leaking again.
 
Was the replacement as straight forward as it seems?

The PO gave me the replacement line when I bought the Jeep. I've started chasing leaks and am just getting around to replacing it. It's from NAPA. I'm thinking I'll put it in now and research the new fittings and braided hose for whenever it starts leaking again.

For snaking the lines in and out, it helps tremendously to support the Jeep on the unibody and let the axle droop.
 
Do elaborate on the braided hose....links?


I actually took a ton of pictures when I installed my trans cooler and braided hose -- never uploaded them, but they are on my camera --

I'll get to it over the weekend and post up some of the important ones here -- I'm pretty sure I have all the part numbers included
 
I actually took a ton of pictures when I installed my trans cooler and braided hose -- never uploaded them, but they are on my camera --

I'll get to it over the weekend and post up some of the important ones here -- I'm pretty sure I have all the part numbers included

Please do, it'd be nice to fix it once and not have to worry about it after that.
 
Was the replacement as straight forward as it seems?

The PO gave me the replacement line when I bought the Jeep. I've started chasing leaks and am just getting around to replacing it. It's from NAPA. I'm thinking I'll put it in now and research the new fittings and braided hose for whenever it starts leaking again.

Piece of cake. Make sure you disconnect the battery cause you will be around te starter when running the line. Also I recommend taking the elbow off the radiator and then removing it will the tool. There most likely will be a lot of gunk in there that will have to be cleaned out so that when you do use that tool it will hit the tabs to release. Also just a little Vaseline to not roll the little O Ring when putting the new one on. At the tranny side you will just squeeze the white plastic piece to remove the old line.
 
Piece of cake. Make sure you disconnect the battery cause you will be around the starter when running the line. Also I recommend taking the elbow off the radiator and then removing it will the tool. There most likely will be a lot of gunk in there that will have to be cleaned out so that when you do use that tool it will hit the tabs to release. Also just a little Vaseline to not roll the little O Ring when putting the new one on. At the tranny side you will just squeeze the white plastic piece to remove the old line.

Sorry tried to edit and messed up.
 
some pictures of the fittings -- more pictures in my album
http://www.naxja.org/forum/album.php?albumid=631

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Heavyopp, what are you using for the adapter at the top radiator port?

I did something similar but just use reinforced oil hose instead of braided line

14mm to AN-6 adapters on the cooler ports, AN-6 to 3/8" barbed fittings for the hoses (90-degree in the rear, 45-degree in the front).

New_Cooler_Lines.sized.jpg


Transmission went into the lower radiator port (already flared so just a hose clamp), then out the top (cut and flared the hard line myself). From there it goes out the air box intake opening and along the crossmember to a B&M 70273 cooler with 1/2" NPT to AN-6 adapters, and more of the 90-degree adapters

BM_70273_Final_Fit.sized.jpg


I also put a Wix magnetic filter on the return after the cooler

Wix_58953_Trans_Filter.sized.jpg
 
Looks like summit racing part # SUM-2206678 for the top port adapter

the bottom one I found easier to use the 3/8th compression adapter over a threaded adapter -- just not much space to make the turn


I also used the BM 70273 cooler -- I like those heavy 1/2 NPT connections
 
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Okay I have been struggling to find an AN-6 adapter for the upper port for a long time, so have a lot of other people.

I found a cooler line and fitting at the junkyard and pulled it to adapt before I saw your Summit fitting. As you can see the Summit fitting is the correct thread in comparison to that fitting. If you have a radiator with a removable adapter then it should work fine

Junkyard_Rad_vs_Summit_Fittings.sized.jpg


However the '01 Mopar HD radiator that I have does not have the adapter fitting. Instead the fitting is brazed to the internal tube, and then secured to the side tank with another nut. The fitting is not removable.

Stock_HD_Rad_Fitting.sized.jpg


In order for me to do an AN-6 fitting, I need a female 5/8-18 invererted flare to male AN-6 adapter, no such creature exists. At this point I don't even think its necessary, but now its like my personal holy grail and I want to try to find one.

Thanks for the link though
 
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