7.3 Transmission Cooler Line Diagram

A transmission cooler line diagram is a visual representation of the path that transmission fluid takes as it flows through the various components of your vehicle’s cooling system. This can be an invaluable tool when troubleshooting transmission problems, as it can help you to identify potential blockages or leaks in the system. In most cases, the diagram will be printed on the underside of the hood or on a sticker inside the engine compartment.

If you cannot find a diagram for your specific vehicle, there are many online resources that offer generic diagrams that will still be helpful.

If you have a 7.3L Powerstroke Diesel, then you know that the transmission is one of the most important parts of the truck. Without a properly functioning transmission, your truck is not going to go anywhere. That’s why it’s so important to keep your transmission in good working order, and one of the best ways to do that is to keep the transmission cooler lines clean and free from debris.

Over time, Transmission cooler lines can become clogged with dirt and grime, which can restrict fluid flow and cause overheating. If you’re experiencing problems with your transmission, one of the first things you should check is the condition of your transmission cooler lines. The good news is that cleaning your transmission cooler lines is relatively easy.

You’ll need a few tools and supplies, but once you’ve got everything together, the process shouldn’t take more than an hour or two. Here’s a quick rundown of what you’ll need:

7.3 Transmission Cooler Line Diagram

Credit: www.ford-trucks.com

Which Transmission Cooler Line is Which?

If you’re having trouble determining which transmission cooler line is which, there are a few things you can check. First, if your vehicle has an automatic transmission, the cooler lines will be different sizes. The larger line is the return line and the smaller line is the supply line.

Another way to tell the difference between the two lines is by checking the fittings on each end. The return line will usually have a 90-degree fitting on one end, while the supply line will have a 45-degree fitting. Finally, you can often tell which line is which by tracing each one back to its respective radiator connection.

The return line will typically go directly to the radiator, while the supply line will go to a tee connector before reaching the radiator.

How Do I Know If My Transmission Cooler Line is Leaking?

If your transmission cooler line is leaking, you will likely notice transmission fluid on the ground where your car is parked. Transmission fluid leaks can also be diagnosed by checking the level of transmission fluid using the dipstick. If the level of transmission fluid is low, it may be due to a leak in the cooler line.

Do You Have to Bleed Transmission Cooler Lines?

Transmission cooler lines are responsible for carrying hot transmission fluid from the transmission to the radiator, where it can be cooled off. Over time, these lines can become clogged with dirt and debris, which can cause the fluid to overheat and potentially damage the transmission. For this reason, it’s important to bleed the lines on a regular basis to remove any build-up and keep the system running smoothly.

There are two ways to bleed transmission cooler lines: manually or with a power bleeder. Manual bleeding is done by opening the bleeder screws on each line and then cycling the transmission through its gears until all of the air has been purged from the system. This method can be time-consuming and messy, so it’s often best left to professionals.

Power bleeding is a quicker and easier way to flush out dirty transmission fluid. This method uses a special pump that attaches to the top of the radiator and forces clean fluid through the system under pressure. Power bleeding is generally considered the more effective option, but it does require some specialized equipment that may not be available to everyone.

No matter which method you choose, bleeding your transmission cooler lines is an important part of routine maintenance that will help keep your car running smoothly for years to come.

Can I Use a Rubber Line As a Transmission Cooler Line?

You can use a rubber line as your transmission cooler line, but there are some disadvantages. First, rubber lines are not as strong as metal lines and can rupture under high pressure. Second, they are not as heat resistant as metal lines and can degrade over time.

Third, they are more difficult to install and maintain than metal lines.

Ford 2002 F250/F350 Transmission Line Replacement

7.3 Transmission Cooler Bypass

When it comes to your car, the transmission is one of the most important parts. The transmission is responsible for transferring power from the engine to the wheels. In order to keep your transmission running smoothly, it is important to have a properly functioning transmission cooler bypass.

The transmission cooler bypass is a valve that helps regulate the flow of fluid in the transmission cooler. When this valve is not working properly, it can cause a number of problems with your car’s transmission. For example, if the valve is stuck open, it can cause your car to overheat and damage the Transmission Control Module (TCM).

Additionally, if the valve is stuck closed, it can prevent proper cooling of the fluid and lead to increased wear and tear on the transmission. If you suspect that your car’s transmission cooler bypass may not be functioning properly, it is important to take it to a qualified mechanic or dealership for service. They will be able to diagnose the problem and make any necessary repairs.

7.3 Transmission Cooler Location

If your car has an automatic transmission, then it likely has a transmission cooler. This is a small radiator-like device that helps to keep the transmission fluid cool. The location of the transmission cooler can vary depending on the make and model of your car, but it is typically located either in front of or behind the radiator.

In most cases, the transmission cooler is located in front of the radiator. This allows air to flow through the radiator and over the transmission cooler when the car is moving, helping to keep the fluid cool. In some cases, however, the transmission cooler may be located behind the radiator.

This can be beneficial as it keeps hot air from flowing through the radiator and over the transmission fluid. Regardless of where your car’s transmission cooler is located, it is important to keep an eye on its condition. If you notice that your car’s fluid is overheating frequently, then there may be an issue with the cooling system and you should have it checked out by a mechanic.

6.0 Powerstroke Transmission Cooler Line Replacement

If you have a 6.0 Powerstroke, then you know that the transmission cooler lines are an important part of keeping your truck running smoothly. Over time, these lines can develop leaks and need to be replaced. Here’s a step-by-step guide to replacing your 6.0 Powerstroke transmission cooler lines:

1) Jack up the front of your truck and support it with jack stands. This will give you access to the underside of the truck where the transmission cooler lines are located. 2) Place a drain pan underneath the transmission cooler line fittings on both sides of the truck to catch any fluid that may leak out when you disconnect the lines.

3) Using a wrench, loosen and remove the bolts that secure the transmission cooler lines to their respective fittings on either side of the truck. Be careful not to over tighten or strip these bolts when removing them – they can be difficult to replace if damaged. 4) With the bolts removed, gently pull each transmission cooler line away from its fitting being careful not to damage either component in the process.

If there is any fluid leaking from either line or fitting, clean off any excess before proceeding. 5) Take your new transmission cooler lines and fit them into place at their respective fittings on either side of the truck ensuring that they’re properly seated and aligned. 6) Using your wrench, hand-tighten each bolt until it is snug against its corresponding fitting taking care not to over tighten or strip them again in this process!

Which Transmission Cooler Line is the Return

If you’re asking which transmission cooler line is the return line, it’s the lower line. The upper transmission cooler line is the supply line.


If your vehicle is leaking transmission fluid, it’s likely that there’s a problem with the transmission cooler lines. Transmission coolers help keep your transmission from overheating, so it’s important to fix any leaks as soon as possible. This blog post provides a diagram of the transmission cooler lines for a 7.3L Powerstroke engine, so you can easily identify where the leak is coming from.

Show full profile


Robert is a lifelong enthusiast of all things automotive. He has been working with wiring diagrams and schematics since he was in high school, and continues to use them as the foundation for his knowledge today.

We will be happy to hear your thoughts

Leave a reply

Enable registration in settings - general
Shopping cart