A hydraulic brake lever includes a body having a bladder chamber, a cavity and a flexible separator mounted between the bladder chamber and the cavity. The flexible separator holds hydraulic oil in a front section of the body and prevents a rear section of the body from contacting with the pressurized hydraulic oil. A cylinder is mounted in the cavity of the body and accommodates a piston set. Thus, a high pressure is kept in the cylinder and is not applied directly on the body. Due to the separating design, the hydraulic oil applied a low pressure on the body. Thus, manufacturing the body is less limited and a manufacturing cost is reduced.