I think Justin was referring to the brake fluid-DOT3. The hydraulic fluid is AW32. The tank has enough hydraulic fluid in it when the mast lifts all the way up and tilts back and forth without cavitating. There is no dipstick because all the tanks are the same capacity and size. It takes alot more fluid to raise the forks 20' than it does to raise them 10'. Make sure the forks are on the ground when you add fluid.