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5 Reasons Why You Shouldn’t Flush Your Own Transmission

Pressure control solenoid or valve control unit of an automatic transmission

It’s lurking there, far under your hood and engine. Your transmission is waiting for service. When it’s so easy to forget that your transmission is hiding under so much of your car’s mechanical systems, it can be neglected. Though it may be tempting to just flush your own transmission during a long weekend, there are several reasons why you should entrust your transmission flush to a shop instead. Let’s take a look at the reasons why you’ll want the professionals on this one.


5 Reasons Why You Shouldn’t Flush Your Own Transmission

Transmission fluid intervals are getting ridiculously long these days, with many vehicles exceeding 100,000 miles. That can make it one of those things that just slips your mind. However, if you’re guilty of putting off flushing your transmission in a timely manner, there are several good reasons to go with a professional shop:

  1. Are you sure that’s the right kind of transmission fluid for your vehicle? It used to be fairly easy to get the right transmission fluid, but as vehicles have become more complex, so have the fluids that keep them running. The wrong transmission fluid can cause your transmission to fail, while the right one keeps it shifting smoothly. Do you want to take the chance of expensive transmission repairs on your knowledge of transmissions?
  2. Before you add that transmission additive, STOP! There are very few transmission additives that really boost performance or allow you to put off a transmission flush, and many of them on the market give you a false sense of security. This can lead you to further putting off a flush, causing even more damage than your questionable transmission additives can cause, leading to expensive repairs.
  3. Do you know exactly what to look for in terms of wear in your transmission? By having a shop handle your transmission flush, you’re also having professionals who know what to look for, keeping an eye out for any wear or damage inside your transmission. This allows you to catch these issues much earlier on, before they become a serious problem. Small issues tend to be a lot less expensive to fix than replacing a failed transmission.
  4. It’s a mess. Flushing a transmission means moving a lot of fluids around. Where are you going to put them in the middle of the process? Where should you return them to? How much cleanup do you really feel like doing in your garage this weekend? Instead of having to deal with the mess and fuss, why not have your transmission flushed by a professional company that takes care of all the mess for you, leaving you with a vehicle that’s all ready to go out into life’s adventures?
  5. Fluid type isn’t the only mistake that can be made. We once had someone come in with a transmission that wasn’t building up hydraulic pressure to shift, because when they couldn’t get the filter to slide cleanly into place, they used the process of tightening the bolts on the pan to push it into place. The gasket wasn’t in the right location, so the transmission wasn’t sealed tightly enough to be able to build sufficient pressure to shift into higher gears. The customer was very frustrated, but we were able to get them on the road again.

By understanding why it’s important to have a professional shop handling your transmission flush, you’ll be able to avoid a lot of the pitfalls of the process, from mess to wear to mistakes in the process. This allows you to get the best possible mileage out of your transmission, instead of having to face an expensive replacement. If you need to have your transmission serviced, why not contact the professionals at Mac’s Radiator and Automotive Service today? With six convenient locations scattered across Oregon and Idaho, you’re sure to find one close to home.



Mac's Radiator is the best mechanic to help you with all of your mechanic needs!  Let Macs help you - we are located in 6 convenient locations, for when you need us close to home, or when you're on the road.  



Portland, OR      (503) 777-4706
Beaverton, OR  (503) 646-2943
Bend, OR            (541) 382-6963
Boise, ID            (208) 344-1722
Eugene, OR        (541) 344-0253
Salem, OR          (503) 364-7129

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