To flush or not to flush, that is always the question. We often get asked how much a flush costs, is a flush needed or if a flush will fix a problem. The answer is quite complex but I will start by saying it costs too much, is most likely not needed, and highly unlikely to fix a problem. The term alone is somewhat scary, I think the term transfusion is more accurate. The cost of a transmission fluid flush usually includes lots of fluid, labor, and the payments on a very expensive machine. It usually does not include a filter or pan gasket or insight on wear. Would you ever change your engine oil without changing the filter? I doubt it. The transmission filter cannot be back flushed. Fluid can only flow in one direction throughout the transmission. In most cases a complete fluid replacement is not needed. Removing the pan replacing the filter and filter seal along with cleaning all contaminants out of pan, cleaning any magnets in pan, identifying any potential concerns in pan or under vehicle, resealing pan and replacing drained fluid has proven to be more beneficial. If a problem does exist a conventional transmission service has far greater chances of resolving and diagnosing them than using a flushing machine. There are some vehicles that change this theory a little. Many newer vehicles do not have a pan, have external spin-on filters or have internal filters that can not be changed without complete disassembly of the transmission. On such vehicles it is best to perform multiple drain and fill services rather than flushing with a machine. This procedure allows gravity and the fluid in the unit to push contaminates out of the bottom of the unit when exiting rather than agitating them with a machine, which may cause them to travel throughout the system, sticking valves and solenoids.
I hope this clarifies the subject a little, any questions please don’t hesitate to call.