Brake drum and rear brake drum for various types of vehicles.Brake drums are usually used in low-end cars and large trucks, and although they are inexpensive, they do not dissipate heat well. When braking downhill for a long time, the brake may fail, so it is usually equipped with a water shower to enhance heat dissipation. The brake drum has a gap and needs to be adjusted regularly, and the coaxial wheels must be the same, otherwise there is a danger of brake bias.