trans cooler lines

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Blackrose

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EDIT: for piece of mind, I have been running standard home depot stainless steel hose clamps with barb fittings on the connections to an added trans oil cooler (I bought a radiator with a built in cooler in addition to the external cooler the jeep already had). No leaks no problems and it has been a couple years now.

Did you replace your lines because of a leak or did you have to put different lines in when you switched to the in-radiator trans cooler? I'm interested in doing the same thing, but I'm not sure if the cooler lines are different for the in-radiator cooler. Are the hoses at the end a different length? If I were to install that radiator would I need different cooler lines?
 

mrlavalamp

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Mine leaked at the crimps.

I just tied the radiator cooler inline with the external cooler.

There is a how to on here somewhere. Ima search and be back

EDIT: couldnt find a how to, I thought I followed one with pictures but if I cannot find it that wont help you much. I did find this: https://www.jeepkj.com/threads/transmission-cooler-modification.64158/#post-738502

Cannot remember which line is "hot" and which is return though, sorry.
 
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Blackrose

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Mine leaked at the crimps.

I just tied the radiator cooler inline with the external cooler.

There is a how to on here somewhere. Ima search and be back

EDIT: couldnt find a how to, I thought I followed one with pictures but if I cannot find it that wont help you much. I did find this: https://www.jeepkj.com/threads/transmission-cooler-modification.64158/#post-738502

Cannot remember which line is "hot" and which is return though, sorry.

Thanks for that info. I'm thinking of waiting until I see how my current radiator does this summer before making the switch. One of my lines also has a very slight leak at the crimp as well, so I might just do it all at once if it gets bad.
 

Leeann

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I replaced the entire lines with the jeep sitting on the ground no problem.

was not that hard really, just a little twisting and turning and cussing and swearing and they were in.


This is what I did a little while ago. Wasn't difficult, didn't require a lot of tools, just took time and patience (and cussing in lieu of patience). I bought Mopar lines on eBay and they weren't that expensive.
 

randymorris

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IMO cutting the crimps apart without damaging the flare and hard line is a bigger hassel.

Once you get them cut apart and the old hoses off, a new hose and those clamps would work just fine. make sure you get hose rated for oils and not any old rubber hose.
Without going and measuring the OD of the hose, those look about right, just confirm the size range matches whatever size hose you put on
yeah, I looked it up already. It’s 3/8th inner diameter hose, so that size should be right. I am hopeful I can do this work next weekend. I started a new job thankfully, and so I may have money again soon. Coronavirus definitely wiped out my bank account.
 

Duster

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I had the leak at the crimps on one line, took a look at the metal parts of the lines and they were all perfect. Looked at what all I thought would have to come out of the way to replace the line set, etc. Then thought I will just go get some transmission hose from Napa and swap the rubber hose out and install regular hose clamps 2 per side.

7 hours later I have one of the rubber hoses replaced. So this was not a wise decision I don't think.

The only way I could figure to get the crimps off was to split them down the sides with a dremel and cutting wheels, then pry them off. I thought they were aluminum. They are not, they are steel on the KJ. 30 discs later I had 3 of 4 cuts made. Spent more time replacing broken discs than cutting. The cooler side crimp I cut on 2 sides and pried off as planned. The crimp on the line coming from the transmission I was able to make the cut on the wheel well side of the crimp, but realized I'd never make the cut on the other side even if I had discs because the other line is in the way. So I took a lot of deep breaths and used a couple of flat screwdrivers and needle nose pliers to flare and pry. I eventually got it where I could have turned it enough to make the other cut. But I just stayed at it and eventually pried it off.

I as far as cutting I made some very small scores in the rubber line. I probably could have just opened some clamps and clamped it down. But after realizing the rubber had hardened and lost it's springiness was probably the reason it leaked in the first place I decided to go ahead and replace the rubber hose section with the new.

I could not even get the old hose off the metal lines. I had to split it with a box knife to get it off. Then I took one look at the ID of the old hard hose and the ID of the new one and realized it was gonna be a long day getting that pushed over the ****** and barbs. So I washed up the net mesh cover from the old line and transferred to the new. Then used it to hold my pair of clamps on each end out of my way. And then it proceeded to take forever for me to get both sides pushed on.

I took one look at the other rubber part and said there is no way. I will wait until it leaks!

I hope it lasts and don't **** cause of course it would pump all your fluid out.

I think we all have the leak on the same line, the passenger side most one. I believe this is probably the hot line coming from the transmission. Gets hotter, then cold weather comes and there is more expanding and contracting.

I lost almost no fluid doing this. A few ounces when I first took the line loose. Then a few more came out of the cooler when I was trying to put the new hose on which totally made a slick mess of everything.

I did want to ask though... the fluid that came out first out of the line really surprised me. It looks sorta Irish Red Ale in color or juicy juice fruit punch if you have never had an Irish Red. Dark red, transparent hint of brown. Checking my fluid with a dipstick, it's always like a transparent with pink tinge. But that is done when it is hot. Cold it's more red cause I checked. But not that dark. I found that weird. Enough that I checked after the test drive to see that both lines coming from the cooler had some temperature and they did so it is passing through.

What came out of the cooler as I was putting the new line on was not as dark either. Maybe it is just that last bit of fluid that doesn't make it out of the line into the cooler sits there after you park? Maybe nothing to it. I just found it strange like I find it strange the fluid on the dipstick is darker cold than hot. I never knew that all these years cause I never tried to check the level cold for any reason because it's not the procedure.

Anyways, I recommend replacing the line set I think. I would imagine you can replace both lines entirely in less time.
 

65Corvair

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I did a "hose" replacement similar to Duster described. I removed the air box, serpentine belt tensioner, radiator fan, and front sway bar to get the most room for the Dremel tool to cut the crimped hose connectors. I didn't have much trouble cutting the crimped ends off the old hose. I did cut into the hose a bit, but my intention was to replace the hose. Overall, it is not a hard job, but it just takes some time. I would do it again, compared to replacing the entire hose/tube assembly.
I used 3/8 transmission cooler line from my local auto parts store to replace the hose.
https://www.oreillyauto.com/detail/c/gates/gates-oil-cooler-hose/gat0/27059

I drove an 80-mile round trip with no leaks so far.

If I see the other hose either start to push off or leak, it will get replaced too with the same method.

Here is the before and after.
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