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Discussion Starter #1
I have a transmission line that is almost worn through, so I pulled it off. I planned on just taking it to a hose company (it was a hydraulic hose) and having them make me a new one, but they aren't cheap and do high quality work. While I was under the truck I noticed one metal line was creased pretty bad from some previous shoddy repair work, and another line was rubbing badly on metal surfaces. I figured I would have the hose company remake me all new hydraulic rubber lines for everything but the cost of that is going to sky rocket. I search Google and found a kit for rubber lines, but it talks about doing a heat exchanger bypass.

So my question is, how can I tell if this bypass has already been done on my truck? Also, if it hasn't been done, do you guys recommend i bypass it? I live in Texas, but my life seems to take me in all kinds of unpredictable directions, including the north in the winter. I don't want to have an issue in -15 weather because I bypassed a heater.

Link to the lines

Thoughts?
 

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The heat exchanger is not a heater, it's a cooler. Guys bypass them all the time, but I, personally, don't recommend it. It does perform an important function.
 

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Discussion Starter #3
The heat exchanger is not a heater, it's a cooler. Guys bypass them all the time, but I, personally, don't recommend it. It does perform an important function.
Ah! Thank you for clarifying that for me. Any idea why they recommend bypassing it? What problems are they trying to ovoid by bypassing?
 

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The heat exchanger can fail internally, allowing coolant into the transmission fluid and transmission fluid into the coolant. It's not something I see very often (I actually can't remember the last one I saw do that), but it COULD happen. That's the main reason why guys delete them.
 

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Significantly cheaper then full send Diesel’s kit. But you have to make the lines yourself. It’s really not all that complicated. And less than half the cost.
 

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It runs cooler without the torque converter cooler? Hmmm....
 

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Discussion Starter #8
I got 3/4 orb fittings to -8an lines and fittings. Will work with or without coolant bypass. I bypassed. Trans runs way cooler.
I wonder why it would run cooler?
Can anyone else chime in on their experiences with bypassing?
Significantly cheaper then full send Diesel’s kit. But you have to make the lines yourself. It’s really not all that complicated. And less than half the cost.
I saw a video where a guy cut the metal lines out and hose clamped rubber lines to the little bit of metal he left leading to the fittings. Is this what you're talking about?
 

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The trans will run cooler because the hot coolant won't be shedding it's heat to the trans fluid in the head exchanger. Now with the heat exchanger removed and the plumbing separated on both the only thing keep the trans temps in check is the trans cooler. Now there have been mixed reviews on deleting the exchanger. Granted yes it takes the fluid longer to get hotter, but if you're in stop and go with no air flow across the trans cooler there's nothing left to keep the temperatures in check. The heat exchanger can kinda keep the temps around 180-200. If you have a good functioning trans cooler that's operating just fine and you are cruising the highway or doing very little city traffic, I recommend deleting. If you are doing 50/50 it's a toss up on it. Mostly city I recommend keeping it. For example me, I want to delete the heat exchanger, but NO ONE makes a heat exchanger deletion kit. I also want to remove the check ball in the line, but I don't know which line or where it is.
 

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Discussion Starter #10
Looked up some diagrams and crawled up under my truck. Looks like mine has already been bypassed. Interesting
 

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The purpose of the heat exchanger (which is actually called the torque converter cooler) is to cool the fluid coming out of the converter, which quite often exceeds engine coolant temperature by a significant amount. Some of the fluid temps coming from the converter even under normal operation can be downright scary. If you're going to delete the exchanger (which I do not recommend), you should have a way to monitor fluid temp.
 

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Discussion Starter #12
Thanks for the responses guys.
Today I went around to part stores trying to gather supplies, only a few of the doorman line were available near me so I searched for parts to make my own. I could not find the right fittings to make it work. The full send kit is on back order so I found a kit online that comes with fittings and the lines that you make yourself, and it is cheaper than the doorman lines would have been. I ordered it.

On a side note I went ahead and changed the transmission filter and found the reverse band to be waaaay out of spec. Explains some of my issues with reverse!
 
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