What Does Flushing A Transmission Mean?

A transmission "flush" is a fairly straightforward process although there are some intricacies to the process that should be noted. In essence, the flush process simply means that the old fluid in an automatic transmission is removed by gravity or under high pressure from the transmission housing and replaced with new automatic transmission fluid.

There are a variety of very good reasons for proceeding with this maintenance process but there are sometimes when it is actually inadvisable. With those two thoughts in mind, here are some of the more notable particulars:

• A transmission flush is intended as a proactive process – In the simplest terms, this means that a transmission flush is not a repair but a needed maintenance process. It will not fix anything that is already wrong with your transmission but it can significantly reduce the probability that something will go wrong with the transmission in the future. In short, a transmission flush is intended to delay further problems but not to completely eliminate them.
• It is not the same as a fluid and filter change – The flushing process, when done correctly, replaces nearly one hundred percent of the old fluid with a new fluid, including the fluid in both the torque converter and the oil cooler lines. It also removes the majority of any metal filings that have built up in the transmission so that they do not cause any further damage. It is certainly not a perfect process but one that extends the useful life of the transmission.
• It is not recommended for every type of vehicle – A flush is not recommended for certain high mileage vehicles. A transmission flush machine uses high pressure along with a cleaning agent to flush the old fluid out of the transmission while simultaneously cleaning the internal parts. During this process, the high-pressure cleaning does such a thorough job that it dislodges dirt and debris that the transmission's internal pump is not strong enough to do. This situation can be somewhat problematic if the debris becomes lodged in a sensitive area.
• It is not a do-it-yourself job – As mentioned above, a transmission flush is typically performed by highly trained technicians who utilize a specialized high-pressure flush machine. If not done correctly, this process can leave debris behind that can result in a catastrophic transmission failure or blow out the internal seals of the mechanism. In either case, the transmission will require a major overhaul – a not inexpensive proposition.
• Is a transmission flush really necessary? – While we would like to be able to say it is an unqualified "yes" or "no," the answer lies somewhere in the middle. It really depends on how much you use your vehicle, how old it is and competent you are at driving it. That is, do you "grind" the transmission or are you able to move it from one position to another without causing any damage.

As you can see, a properly performed transmission flush requires experience and expertise as well as the proper equipment. Do not attempt one unless you are well versed in its complexities or you will pay the price in a damaged transmission.

For more specific information on the basics – and the intricacies! – of properly flushing the transmission of your vehicle, please contact us at Express Automotive Services.