When bypassing the radiator transmission cooler with an external trans cooler… Is it necessary to plug off the old trans cooler line holes in the radiator? Thanks
True dat... but I worked in a real radiator shop for a while and saw thermal bypass valves in a lot of those coolers too and you'd never know about it if you didn't take the header off the cores.The pressure port will typically be hotter than the pan...pressurizing fluid causes heat (you know this). But, you take temp readings on your K5 at the pan?
Many (I might go as far as to say most) real trucks have standalone trans coolers. The Allison in my DMAX is that way. And, was probably under sized for heavy towing. Running it through the radiator would've just compounded heating issues, potentially dragging the engine cooling down with it. I installed a much larger trans cooler, as well as an enormous engine oil cooler.
In a traditional truck cooling stack, the trans cooler is out front. It gets the coolest air to reject the maximum amount of heat, always. Then the a/c condenser, charge air system if equipped, and finally the radiator. Difference here, versus a trans cooler in the rad, is that the heat from the trans isn't directly put back into the cooled engine coolant. When designing the powertrain system, the engineers deemed it OK for the trans cooler to lead the way even when ambient temps could be sub zero, in rain, or snow. They didn't seem at all worried about a trans that is too cool.