A brake in which the friction is supplied by a set of brake shoes or brake pads which press against a rotating drum shaped unit referred to as a brake drum. There are several particular differences among brake drum kinds. A "brake drum" is normally the definition provided if shoes press on the inner exterior of the drum. A "clasp brake" is the term utilized to describe whenever shoes press next to the exterior of the drum. Another kind of brake, called a "band brake" utilizes a flexible belt or band to wrap all-around the outside of the drum. If the drum is pinched in between two shoes, it could be referred to as a "pinch brake drum." Similar to a standard disc brake, these types of brakes are rather uncommon.
Prior to the year 1995, old brake drums required constant adjustment regularly to be able to compensate for shoe and drum wear. "Low pedal" or long brake pedal travel is the dangerous outcome if modifications are not done sufficiently. The motor vehicle could become dangerous and the brakes could become useless if low pedal is mixed with brake fade.
There are several various Self-Adjusting systems for braking obtainable nowadays. They can be classed into two individual categories, the RAI and RAD. RAI systems are built in systems that help the device recover from overheating. The most popular RAI manufacturers are Lucas, Bosch, AP and Bendix. The most well-known RAD systems include AP, Bendix, Ford recovery systems and Volkswagen, VAG.
The self adjusting brake will normally just engage if the vehicle is reversing into a stop. This method of stopping is suitable for use where all wheels use brake drums. Disc brakes are used on the front wheels of vehicles these days. By operating only in reverse it is less likely that the brakes would be adjusted while hot and the brake drums are expanded. If tweaked while hot, "dragging brakes" can happen, which increases fuel expenditure and accelerates wear. A ratchet mechanism that becomes engaged as the hand brake is set is one more way the self repositioning brakes could operate. This means is only suitable in functions where rear brake drums are used. If the emergency or parking brake actuator lever goes over a specific amount of travel, the ratchet advances an adjuster screw and the brake shoes move toward the drum.
There is a manual adjustment knob located at the bottom of the drum. It is usually adjusted via a hole on the opposite side of the wheel and this involves going under the lift truck along with a flathead screwdriver. It is of utmost significance to be able to move the click wheel correctly and adjust each and every wheel evenly. If uneven adjustment occurs, the vehicle could pull to one side during heavy braking. The most effective way in order to make certain this tedious task is accomplished carefully is to either raise each and every wheel off the ground and spin it by hand while measuring how much force it takes and feeling if the shoes are dragging, or give everyeach and every one the same amount of manual clicks and then perform a road test.
Click to Download the pdf