2000 K2500 trans cooler questions

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upper_tanker

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2000 k2500 plow truck 4L80E, trying to hook back up the radiator trans cooler after bypassing it in hopes that it was the cause of the high temps before replacing the entire radiator. It wasn't, so now I want to hook the cooler lines back into the radiator since I added a Derale cooler with fan after I cut the trans cooler lines. I'm expecting hooking the lines back to the radiator will help cool it even more now.

So now, I have both trans lines cut, flared with rubber trans hoses ran to the Derale aftermarket cooler. I have a few questions that I'm hoping to get some help with. The truck is about an hour away and I won't be getting to it until next weekend so I'm hoping to have at least most of the parts in my hand before I start on it if possible.

1. From what I've read, the front outlet on the trans is the pressure port, and the rear is the return. Is this true?

2. Should I put the radiator cooler after the trans or after the Derale?

3. Whatever I do, I would like to buy a new line for whichever trans outlet is going to the radiator cooler if I can find one. Both of mine are cut for the rubber trans hoses so I'd like to replace it with a normal store bought line if possible. Any ideas what these are called? I think the only lines I could find were from trans to aux cooler, nothing to radiator.

4. If I can't find a store bought line, any idea how to find what size/thread pitch the fittings/line is that go into the radiator are? Again I'd like to have everything in my hands before next weekend since I won't have much time to do this. I can always get the two fitting, hard line, and a few pieces of trans cooler hose with FI hose clamps and make it work. Eventually I'd like to do braided AN line but that probably won't be this year.

REALLY hoping this helps bring my temps around 200-205 max. Now, sometimes it climbs to around 215 even after a trans rebuild last year and the Derale cooler. Before the Derale, 225-235 was not uncommon in technical parking lots.
 
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L31MaxExpress

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Radiator cooler before the auxiliary cooler. If you are not already, you should be using 4x4 LOW range when plowing to take the load off the transmission and torque converter. When you are stalling the converter and not moving anywhere it builds heat faster than any cooler setup can reduce it. You want as much torque multiplication as possible from the drivetrain not the converter. When you are at heavy throttle and at low speeds the converter is acting similarly to a dyno absorber, generating tons of BTUs of heat from slippage.
 
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