How to Replace Transmission Cooler Lines

Transmission cooler lines are the essential parts of a vehicle. They circulate the transmission fluid of your vehicle to the radiator. Here, the fluid is cooled and then directed towards the transmission lines for re-circulation. It is important to keep a watchful eye for warning signs that indicate the replacement of transmission cooler lines. One of the most important sign is the appearance of the reddish-colored fluid leaking underneath your vehicle. It is imperative to replace transmission cooler lines as soon as you find the leakage in order to avoid complications in the future. The leaks may get worse, and make the transmission of your vehicle vulnerable to overheating. This also means spending more money on repair. The task of replacing transmission cooler line is a little messy, but not difficult. The steps to replace the transmission cooler lines are given below.

Things You'll Need

  • Jack
  • 2 jack stands
  • Flare nut wrench
  • Drain pan
  • Transmission fluid

Step 1: Block the Rear Wheels

Employ the parking brake of your vehicle and block any one of the rear wheel. Use a jack underneath the front portion of the vehicle and raise it above the ground with enough distance to ease the positioning of the jack stand right under the frame. If you are using a bumper jack, raise each side independently.

Next, crawl underneath the vehicle to locate the lines. These are metal lines that connect the transmission of your vehicle to the bottom of radiator. Under the fittings of radiator, place a drain pan to collect the fluid. Do not use the drain pan without the drain plug. When the fluid stops draining, remove the pan by undoing its bolts.

Step 2: Remove the transmission cooler lines

Use a flare nut wrench and disconnect the fittings from the sides of the transmission. Put the wrench's open end on the cooler line and push the wrench down until it reaches the nut which secures the transmission line fittings. At the end of each transmission line, you will find a nut. Loosen it to remove the lines from the transmission. Remove both the transmission lines from bottom of the radiator. Use the same steps to remove the lines from bottom of the radiator. Pull each line out from the transmission.

Step 3: Attach new Lines

Attach the new transmission cooler lines the same way that you removed it. Make sure that the connections are secured firmly in place. Now, remove the jack stands and lower the vehicle. You need to gauge the amount of fluid that remains in the drain pan. Add exactly the same quantity of transmission fluid to the vehicle’s transmission lines. 

Step 4: Check the Transmission Level

Run the vehicle until it gets warm and use the dipstick to check the level of the transmission fluid. Add more fluid if it is required. Once you are finished, you have successfully replaced the transmission cooler lines of your vehicle.