Transmission Flush Instructions...

Discussion in '1st Synthetics' started by 1st Synthetics, May 3, 2009.

  1. 1st Synthetics

    1st Synthetics Epic Member 5+ Years 1000 Posts

  2. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    Just a quick note on flushing your tranny. It is impossible to replace the all the old fluid by flushing through the total capacity amount of new fluid. What I mean by that is if your 4L60E holds 12 quarts of fluid for instance, flushing 12 quarts of new fluid in to your transmission will only remove approximately 8 quarts of the old fluid. The reason for this is in order to get all the old fluid out of the torque converter you have to drain it out, providing your torque converter has a drain plug. (most converters do not have drain plugs)

    So, in order to flush out the old fluid the new fluid is added in through the sump and is sucked up through the filter into the torque converter. The new oil mixes with the old oil in the torque converter and then exits the torque converter as lube oil out the cooler line to the radiator. This oil that is being dumped is actually a mix of old and new oil!

    The bad news is you actually loose or sacrifice several quarts of new oil in order to get all that old oil out. Keep in mind the older and dirtier your ATF is the more new fluid you will sacrifice in order to ghet your transmission back to 100% new oil.

    The lesson: Service your transmission before the oil gets dirty. If you service your transmission every 24K you will never have to flush your transmission. Just a pan drop and filter change with around 5 or 6 quarts of ATF is all you will need.
  3. Fender Bender Intl

    Fender Bender Intl New Member

    good idea thanks for the instructions i am going to try that
  4. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    Glad to help out!

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