How can I Stop My Transmission From Leaking Fluid?

Stop transmissino leakHave you ever looked under your car and found that it was leaking some sort of fluid that you didn’t even know your car had in it?  Most of us know engine oil is brown or black, coolant is usually green, but you usually don’t see a red fluid.  Automatic transmission fluid is still oil, but usually thinner than engine or gear oil and tinted red in color.  If you’ve found this under your car, then you most likely have a transmission leak.

To check for a leak in your automatic transmission, you can do a visual inspection to try and find the leak point.  Here are some of the most likely places to check:

Automatic Transmission Leak Points:

  • Drive shaft seal
  • Transmission pan seal
  • Input shaft seal
  • Valve body seal

Transmission leak fixChecking your transmission fluid level can also be confusing.  Unlike your engine oil your transmission fluid level needs to be checked while your vehicle is parked and running.  The dip stick will often have a red cap on it and be towards the rear of the engine near the firewall.  There will be 2 different level indications on the dip stick, one for when the fluid is cool, and one for when the fluid is warm.  Your automatic transmission fluid level should indicate in the “cold” range when you first start your vehicle and haven’t yet driven.  It should indicate inside the “hot” range after you’ve driven your vehicle relatively hard, for example, up a long hill, towing, or with the transmission in a lower gear to increase engine RPM.

Once you’ve identified your leak either by a low fluid level or visual inspection, the next question is: How much will this cost to fix?  If you let your transmission operate with a low fluid level, it will cause it to start shifting hard, but eventually will cause permanent damage and could cost thousands to replace.

The best way to prevent these high repair costs, and avoid having to add transmission fluid every few days to your vehicle is to use BlueDevil Transmission Sealer.  BlueDevil Transmission sealer is added directly to your automatic transmission with no need to do a fluid change.  Just add BlueDevil Transmission Sealer and it will work as you drive to seal your leak.  As you drive, Transmission Sealer will be absorbed into the worn out seals and gaskets in your transmission restoring them to their original size and sealing properties.

You can purchase BlueDevil Transmission Sealer at or find it at your local pBlueDevil Transmission Sealerarts stores:

  • Bennett Auto Supply
  • Prime Automotive
  • O’Reilly’s Auto Parts
  • Pepboys
  • Car Quest Auto Parts
  • Advanced Auto Parts
  • NAPA
  • Autozone


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6 comments on “How can I Stop My Transmission From Leaking Fluid?

  1. David Laube on said:

    Can I use Blue Devil oil stop leak to seal an automatic transmission pan gasket?

  2. I have a 2002 Acura RL (front wheel drive). Differential has a small leak. Not leaking from the front cover so it has to be a seal leak. Having to top-off monthly. Do you have a product that could stop the leak?

    • The correct product to use would be the BlueDevil Oil Stop Leak. Keep in mind, you will need to add about 1 ounce of product per quart of capacity.

      Feel free to contact us with any questions.

  3. Mason foster on said:

    I have a 1972 Chevy El Camino V-8 Automatic that is leaking at front seal what do I do to fix that

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