Transmission Cooler Installation Tips for a 2007 Toyota Tacoma
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Question:
I have the D13501 cooler. Does it matter if the lines are facing up or down when installed? Does it matter which line goes where? Is there a flow pattern? Should I use the line from the transmission that is located lower or higher going into the radiator to put in line.Colder or hotter line?
asked by: Randy B
Expert Reply:
Orientation of the inlet and outlet ports does not matter, and it does not matter which line goes where. Your best bet is to figure out the best mounting situation for the easiest connection to your vehicles transmission fluid return line. If you can mount the cooler with the inlet and outlet ports up you will get slightly better cooling performance, but testing has shown that there is only a difference of 2 or 3 degrees from any other position.
Transmission coolers are straight flow through devices so direction of flow does not need to be considered, either port can be used as inlet or outlet.
Normally, the lower line coming out of the OEM radiator tank mounted cooler is the return line. Check first to be sure though. With the engine cold, start the engine and let it run for 10 seconds while shifted into drive. Then, put it back into park, shut the engine off and remove the keys. Now, feel both transmission lines, the cooler line of the two will be the return line.
If you have metal transmission lines, the easiest method for installation of the cooler would be to measure the outer diameter of the return line and use compression fittings, like part # D13032 to attach the hoses. Most transmission lines are 3/8 inch O.D. but you should measure to be sure. To install the compression fittings you will need a tubing cutter and two compression fittings properly sized to fit on the cut ends.
We have a very informative video that shows this type of installation that should be helpful. I also added a photo showing the best cooler location and a typical compression fitting installation drawing.

Product Page this Question was Asked From
Derale Series 8000 Plate-Fin Transmission Cooler Kit w/Barb Inlets - Class II - Efficient
- Transmission Coolers
- Plate-Fin Cooler
- Small SUV
- Standard Mount
- 11W x 5-3/4T x 7/8D Inch
- With 11/32 Inch Hose Barb Inlets
- Derale
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