no idea it is probably using the brake fluid
yes
In the gas tank. I have 2001 Echo.
2001 Toyota Echo doesn't have a timing belt.
http://www.carspace.com/guides/Toyota-Echo-How-to-change-oil
http://pdftown.com/2000-2002-Toyota-Echo-Service-Manual.html
$250-300
You can only adjust the clutch pedal. You can adjust position and range just on top of the pedal.
3.5 Liters
Depends on the fluid. 3.6 liters for oil.
manual recommends Dot 3.
see link