How to Install a Transmission Cooler

by Thomas West

An auxiliary transmission cooler is actually a small radiator that a vehicle's transmission fluid is routed through. This dissipates and cools the fluid and may keep the transmission from overheating. Vehicles that benefit from the addition of a transmission cooler include vehicles that tow or haul heavy loads, especially in hot weather. Without a cooler mounted in the engine compartment of a vehicle, these types of activities can overheat a transmission, which can greatly reduce its overall life.

Peel the backing from the rubber mounting pads. Press the pads into place on the mounting flanges on each corner of the transmission cooler. Place a few wraps of Teflon tape around the threads of the cooler fittings. Screw the fittings into the mounting holes in the cooler and tighten with an adjustable wrench in a clockwise direction. Do not over tighten as this could damage the cooler.

Open the hood of the vehicle. Hold the cooler to the front of the radiator, or the side closest to the grille. Push the zip tie connectors provided with the cooler through the back side of the radiator, then through the lock tabs mounted on the flange of the cooler. Pull the zip ties (there are usually four) tight so that the cooler is mounted solidly to the front of the radiator. Cut off the excess length of zip tie with a utility knife.

Locate the vehicle's transmission return cooling line, which is mounted to the bottom of the vehicle's radiator. Cut the rubber return hose in half with a utility knife. Push a barbed connector provided with the cooler into each end of the cut hose until fully seated.

Push the end of the rubber hose provided with your kit onto one of the barbed connectors installed in step three. Push the other end of the hose onto one of the connectors on the transmission cooler. Repeat this procedure to connect the barbed connector in the other end of the cut hose to the other connector on the transmission cooler. Make sure all connections are fully seated by pushing the hoses onto the connectors.

Start the engine on your vehicle. Check the cooler and the hose connections for leaks. Drive the vehicle approximately five miles to warm up the transmission. Open the hood and check the transmission level using the transmission dipstick. Add transmission fluid to bring the level back up to the "Full" mark. Replace the dipstick and close the hood.

Items you will need

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