I do it every year.
Recommended every 25,000 miles
100K miles transmission oil flush & change.
The transmission fluid on a Toyota Sienna should be changed every 100,000 miles. This helps to prolong the life of the transmission and improve performance.
You need to flush the power steering fluid on a 2003 Toyota Highlander every two to three years. You should check the fluid levels weekly.
You should change your automatic transmission fluid in Toyota gearbox at least after every 30,000 miles.
If it is an automatic transmission every 30 thousand miles.
ten thousand miles
50,000 mi
Urine because you can change the fluids often.
Every 15,000 miles.
flush and change cooling system liquid every 2 years. use correct liquids for your vehicle.