How to Identify Transmission Fluid Return Line for Installing Supplemental Cooler
Updated 08/06/2018 | Published 08/03/2018 >
Question:
I have a 2018 Toyota Tacoma with the 4cylinder 6 speed automatic transmission. It has the transmission lines running to the radiator from what I can tell. Is there a schematic that shows which is the feed and return? We bought a cooler to install enroute from etrailer and I would like confirmation on which line is which please
asked by: Brett
Expert Reply:
The surest way to find the return line in a transmission cooler system is simply to run the cold engine for about 15-seconds while it is in gear. Then immediately feel the two transmission lines. The cooler of the two is the return line that should be used for installation of a supplementary cooler such as the Derale # D13503.
Help articles and an install video are included for you.

Product Page this Question was Asked From
Derale Series 8000 Plate-Fin Transmission Cooler Kit w/Barb Inlets - Class III - Efficient
- Transmission Coolers
- Plate-Fin Cooler
- Mid-Size Truck
- SUV
- Van
- Standard Mount
- 11W x 8-3/4T x 7/8D Inch
- With 11/32 Inch Hose Barb Inlets
- Derale
more information >
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