If you own a vehicle with an automatic transmission, chances are that you will need to perform a transmission flush in the future. Letting your transmission fluid get old and dirty can have dire consequences for your car, so it is imperative that you keep your fluid fresh and clean. Flushing the system helps to ensure that it is free of debris and contaminants so that your transmission continues to operate smoothly for years to come. Maybe you have checked prices on a transmission flush at the local repair shop and decided that you will tackle this maintenance yourself. If you have some automotive experience, this procedure is not extremely difficult and could save you a couple hundred dollars. Keep reading to learn how.
What is a Transmission Flush?
There are two ways to get new fluid into your transmission. The first is the traditional drain and refill method. This involves removing the pan from the transmission and letting the fluid drain out on its own. Some pans even have a drain plug that makes this process very easy. It is no more difficult than changing your engine oil. Simply unscrew the plug, drain the fluid, and then refill with new fluid.
The problem with the drain and refill method is that it does not remove all the old fluid. As much as 30% of the old fluid remains in the torque converter and other parts of the transmission. So, you really are not getting completely brand new fluid into the system. Many mechanics recommend that you perform another drain and refill 10,000 miles after the first in order to more fully get new fluid into the transmission.
A transmission flush completely removes all the old fluid from the system so that you refill with all new fluid. During a flush, the old fluid is removed by force. This is either through the use of a vacuum type pump that sucks all the old fluid out or by using the force of the transmission itself to pump out all the old fluid. The pressure of the fluid removal also cleans the screen inside your transmission of debris so that you do not have to remove the pan for cleaning. If you plan to do this procedure yourself, you will likely be using the latter method as most people do not have access to vacuum equipment.
Many people wonder if you really need to change the fluid in your transmission at all. The answer is a definite yes! While the service intervals vary by vehicle, this is a service that is required for all automatic transmissions. Some vehicles may require it every 40,000 miles while others are only every 100,000 miles. Either way, you need to make sure that you follow your manufacturer’s recommendation to help extend the life of your transmission.
How to Perform a Transmission Flush
The first step to performing your own transmission flush is to make sure you have the proper tools and plenty of transmission fluid ready before starting. Once you start the process, things will move quickly and you have to be ready to handle each step. Now, you should locate the transmission cooler lines that go into the radiator and also make sure you see the filler neck for the transmission so that you know where to put new fluid.
Go ahead and remove the transmission cooler line that runs into the radiator and place the end into a 5 gallon bucket. This is where things begin to move quickly. You’ll want to start the car so that the transmission begins to pump all the old fluid out of the system. As soon as the old fluid starts pumping out of the system, you need to begin adding the new fluid back into the filler tube. You never want things to run dry as this could be detrimental to your transmission.
Refer to your owner’s manual for the capacity of your transmission. Once you have added about 80% of the capacity back in new fluid, shut the vehicle off. Reattach the transmission cooler line to the radiator, and start the car again. Let the car warm up and then shift through the gears, putting the car back into Park at the end of the shifting. Recheck the transmission fluid and top it off if it needs it. Make sure there are no leaks from the line you reattached, and you are all done!
How Much Money Can I Save?
If you have a shop perform this repair, it should cost you anywhere from $250 – $400. By doing this on your own, you will only need to pay for the fluid. You might be wondering, “How much is transmission fluid?” Thankfully, it’s only a few dollars per quart. Depending on how much your car needs, you can probably perform this maintenance item for $50 – $100. When you are done, you will have saved a couple hundred dollars and feel a great sense of accomplishment!