How to Replace Transmission Cooler Lines Like a Pro


Jul 01st, 2020

How to Replace Transmission Cooler Lines Like a Pro

The transmission cooling line plays a significant role in the proper functioning of a vehicle, and sadly, it is also one of the oft-neglected parts. Also called a cooler line or simply transmission line, its primary task may be guessed from its name — it connects the radiator to the transmission while keeping the system cool. 

Cooling lines are made of composite metal or aluminium and rubber pipes. They are manufactured to handle hot fluid and withstand wear and tear longer. However, like any mechanical parts, they are prone to malfunctions too. If the transmission line stops working or is damaged permanently, the performance of your vehicle will be undermined. The most common outcome is overheating of the transmission, which may then quit working if the condition persists.

Symptoms of Bad Transmission Lines

Prior to completely malfunctioning, the defective lines will start leaking. So if you notice a red or orange pool of fluid where you parked your car, it tells you to have your car’s transmission or its cooling lines inspected for leaking fluids. If you experience difficulties shifting into gear or observe delays when shifting, then you ought to immediately act on it for your safety when driving. 

It’s important to catch the problem at that stage or earlier. Don’t wait till you smell something burning from an overheating transmission. Once it starts releasing a lot of liquid, exudes burnt smell and approaches complete malfunction, it will have already brought substantial damage to the transmission. Thus, once you notice minor issues with the cooler lines, it is best to replace them right away. 

Step by Step Guide to Replace the Cooler Lines

1. Raise the Vehicle

It would be best to work on level ground to ensure that your vehicle does not lean too much on the jack when lifted. The place should be well lit. Make sure that you have all the protective gears required. 

The first task is to raise the vehicle to give you full access to what is underneath. You can use two jack stands to raise the front of your car; a ramp would be perfect. 

2. Drain the Transmission Fluid

Once the vehicle is in a steady position, you may start draining the transmission liquid. Separate the clasp that holds the transmission line set-up. Remember to put an oil skillet underneath. 

3. Remove the Old Line 

When the oil is completely drained, you need to remove the old transmission line. You will require a wrench to do this. Release the nut that connects the transmission line. It may take some force to do pull and remove the old lines. 

Remember which end was attached to the radiator and which one went to the transmission. Also make a mental note of the hangers that held the line. Better yet, take a photo before removing the lines.

Expect more trickles of fluid where you detach the cooler lines. Wait until fully drained. Afterwards, you may spray the joint with brake cleaner to remove grit and dirt. 

4. Install the New Cooler Line 

It’s now time to connect the new transmission line – one end to the radiator and the other end to the transmission. Use a wrench to secure the nuts. Use the same hangers where the original line was suspended from. 

7. Replenish the Transmission Fluid 

After doing all the steps, you will need to refill the transmission with the recommended fluid as specified in the manual.

8. Double-check 

Lower your car and examine for issues, particularly for leaks. On the off chance that you find liquid dripping, it implies that the transmission lines might not have been appropriately connected. In that case, you may need to tighten connections or repeat the process.

Get Your Cooler Lines and Other Car Parts from a Reliable Source

Don’t be tempted to use any available hose. Instead, you should research the size, material, and other specs designed for your vehicle. It's important to find the correct replacement before attempting to replace the lines. 

Visit your trusted auto shop, or you may also check out It offers a smart way to search for parts nationwide, saving you a lot of time. What you need to do is request for parts to get quotes from the best auto parts sellers and wreckers nearest you, wherever you are in Australia!

By Ahmed Humayun