Hyundai Elantra Transmission Oil Cooler 25620-F2000

Replacement automatic transmission oil cooler for the 2017-2020 Hyundai Elantra (1.6L and 2.0L), 2019-2020 Hyundai Veloster 2.0L, and 2017-2018 Kia Forte 2.0L. It supersedes OE part numbers 25620-F2000 and 181041-D00, so it mounts on the factory brackets and lines up with the stock cooler line routing instead of forcing you to fabricate a bracket or splice hose.

This is a 6-pass tube-and-fin aluminum core. The cooler sits low and forward on these cars where it eats road debris and winter salt, and the usual failure is a weeping seam or a stone through a fin pack rather than an internal restriction. Symptoms are a slow drip of red fluid onto the crossmember, a low fluid level you keep topping off, and eventually a harsh or delayed engagement once the pump starts pulling air. A mushy 2-3 shift and a transmission that shifts fine cold and gets lazy after twenty minutes on the highway both point at the cooler circuit too.

Replace it as a unit rather than trying to epoxy a seam. Drain the circuit, unclip both cooler lines, pull the two mounting bolts, and transfer the rubber isolators over to the new core. Refill through the fill plug to the factory level with the correct SP-IV or SP-IV M fluid for your unit and check for weeps at both fittings with the engine at operating temperature before you put the splash shield back on. Pressure tested aluminum construction; bolt-on installation with no modification.