DIY Transmission Flush

If you are reading this article, then you already know that the transmission fluid in your car needs to be changed. However, many people think that you have to take your car to a repair shop to have this done. That is not necessarily the case. With a little research and planning, you can perform your own transmission flush and have your car running smoothly for years to come. Keep reading and you will be ready to tackle this job in no time.

Why Change Your Transmission Fluid?

Just like with your engine oil, transmission fluid changes are essential. Over time, this fluid can lose its cooling and lubricating properties. This can create additional friction and heat within your transmission. Heat is a transmission’s worst enemy, so you should do everything possible to keep it from overheating. Old fluid also gets dirty and contains contaminants that need to be removed from the system. Keeping your fluid clean and fresh is one of the keys to extending the life of your transmission.

Steps to Performing Your Own Transmission Flush

There is more than one way to change the fluid in your transmission. If your car is older and has never had a change before, then consider doing a simple fluid change instead of a flush. Here is how you would tackle that. Make sure that your car is supported on jack stands before getting under the vehicle to perform this service. Next, locate the transmission pan and remove the bolts from one side of the pan. Be ready as fluid will start to leak out, so make sure you have a large drip pan underneath. Once the screws from one side are removed, then loosen the screws on the other side so that you can tilt the pan and let the fluid drain. When no more fluid is draining, remove the remaining bolts and drop the pan from the vehicle. Thoroughly clean the old gasket from the pan and the bottom of the transmission. Replace the filter with a new one, place a new gasket on the pan, and replace the pan. Refill the transmission with new fluid, and you’re read to go!

If you’re looking to perform a transmission flush instead, then you can do that on your own too! A flush will remove all the old fluid, unlike a fluid change which leaves 30% or so of the old fluid behind. A flush also helps to remove any debris or contaminants contained in the transmission. Here’s how you tackle a transmission flush.

Again, make sure your car is fully supported with jack stands before getting underneath. Next, locate the transmission cooler lines. They usually run from the transmission to the radiator or a separate cooler near the radiator. Make sure you read through all the instructions before you get started as things move very quickly during a transmission flush. Go ahead and get your new transmission fluid ready and move the caps and seals from the bottles. Remove the transmission cooler line that runs away from the transmission at the radiator. Place the end into a large catch pan or bucket. Place a funnel into the filler tube of the transmission and be ready to pour in your new fluid. Start the car and fluid should begin to pump out of the line that you removed. Go ahead and start pouring the new fluid into your funnel and try not to let it run dry as this could be detrimental to your transmission. When you have added almost all of the new fluid, shut off the car and replace the transmission line. Check the transmission fluid level and top off if necessary. Congratulations! You just performed your own transmission flush!


Keeping your automatic transmission fluid, or ATF, clean and fresh is essential to having your transmission operating smoothly for many years. If you are looking to save some money on this service, it is absolutely something that you can do yourself with some basic tools even if you have very little mechanical experience. Do your research first so that you know exactly what you are tackling before you get into the job. If you do this beforehand, then you will be prepared and ready to handle a transmission flush, and you will feel a great sense of accomplishment when you are done. Have fun turning those wrenches!

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