Open the hood of your Sienna.
Locate the brake fluid reservoir. It is a clear or translucent plastic container that is usually located near the master cylinder, which is on the driver's side of the engine compartment.
Check the fluid level. The fluid level should be between the "MIN" and "MAX" marks on the reservoir.
If the fluid level is low, you will need to add brake fluid. Use only DOT 3 brake fluid. Do not overfill the reservoir.
Close the hood of your Sienna.
