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Hengding wheel hub bearing teach you how to maintain the brakes : 1 . Ensure good braking performance Good braking performance of the car , requiring at any speed when traveling through braking measures , in a very short period of time and distance, promptly reduce the speed or stop. Good braking performance for improving the average speed of the car and has an important role to ensure traffic safety . The main measures to improve the braking performance are: ( 1 ) shorten the braking distance : In the course of the brake , the brake shoe friction pads and brake drum wear , the brake gap becomes larger . Brake system response time increases , will cause the brake retardation and lack of braking force , the braking distance is extended , the braking performance degradation. Braking, brake friction generated by the size , in large part also depends on how much brake shoes and brake drum contact area , the contact area increases , the braking force is growing faster time , braking performance will improve braking distance will be shortened . Under normal circumstances , a greater frictional force when the contact area with the brake drum brake shoes should be above 80 %. Use, because the brake wear after leaving the gap increases, adjustments must be checked . ( 2 ) prevent the brake deviation : Brake , the car automatically deviate from the original direction of travel , a phenomenon called brake deviation. Once the brake deviation is likely to cause a crash , or even roll down the road off the ditch and other serious accidents. To improve the stability of the brake , to ensure traffic safety, emergency braking , the car has allowed significant deviation phenomenon . Braking deviation of the main reasons for the front left wheel braking force varies around the center of gravity on the formation of rotational torque braking, making the car turn the trend has occurred , and therefore prone to brake deviation phenomenon . To avoid deviation , in use , the wheel brakes should be noted that the gap around the brake shoe return spring tension must be consistent . Replacing the friction films, should be used the same model and batch processing accuracy and contact surfaces shall comply with the requirements. And to prevent the emergence of hardened layer friction plates , stained with oil , brake drums out of round or grooves , etc. 2 . Eliminate shimmy Some cars under certain driving conditions , the steering wheel will appear shimmy phenomenon . Steering wheel shimmy so manipulated conditions worsen , it is difficult to control the direction of severe , affecting traffic safety , and will increase tire wear and reduce the life of the steering system . As the front wheel shimmy , had to reduce speed, and thus the transport efficiency decreases. ( 1 ) attention to the selection and control of road speed : When the car in the rugged road, the front wheel up and down easily . In general , the driving system and steering system of the buffer structure and the inner friction effect, when the uneven surface by the vibration damping will own , the driver turns the steering wheel only appropriate , to restore the straight-ahead position . In use, should pay attention to choose the road , reduce or avoid the road -induced vibration reasons , causing the front wheel shimmy . In addition , the speed should be controlled to prevent the vibration frequency of the wheel caused the outside world , and with the Department 's own steering system close to the vibration frequency , resonance, so shimmy intensified, resulting in an unstable state cars . ( 2 ) automobile wheel balancing should be : Wheel mass distribution is uneven, rotate it is uneven, which is much larger impact on the steering wheel shimmy . Therefore, the wheel itself is an important reason for the imbalance car front wheel shimmy . Wheel imbalance is mainly due to : tires, rims and repair process in the production of material unevenly distributed , rims accuracy error , such as incorrect tire assembly . When servicing , respond wheels for balancing checks. General car ride imbalance should be less than 500-1000g · cm; truck imbalance is not greater than 1500-2000g · cm. It should be noted in the maintenance of tire repair should not be installed in the front , in order to avoid shimmy and ensure traffic safety. After the muddy road car driving, the tires should be promptly removed soil to prevent the clay on the wheel , wheel balancing destruction . ( 3 ) To correct wheel alignment : In use, if the damaged wheel alignment will not only affect the stability of the car to keep driving straight , meanwhile, could easily cause shimmy . The main factors affecting the wheel alignment change is deformed front axle , leaf spring displacement and soft and so on. Beam current is too large, easily lead to shimmy . Leaf spring displacement and allow to soften the caster angle is reduced, even after a negative tilt , which is an important factor in causing shimmy . If this happens , you can replace the leaf springs or add a mold shaped gasket between the leaf springs and the front axle , in order to restore the kingpin inclination. In addition, loose wheel bearings , chassis deformation shimmy have a certain impact on the front wheels. ( 4 ) There should be no mechanical steering Songkuang : 3, the car steering loose joints , such as the steering arm nut and bolt loose steering bracket , steering bearing wear , longitudinal spherical rod and tie rod wear, as well as the engagement gap is too large , etc., can cause shimmy . It is understood Hengding wheel hub bearing unit to check the brake system steps: STEP1: Check the brake fluid reservoir volume . The amount of the brake fluid reservoir tank should be between the upper and lower engraved lines . If the lack of brake fluid, should add the same species, the same brands and models of brake fluid can not add other types of brake fluid or alcohol substitutes. STEP2: Check the hydraulic brake system brake pedal " foot feeling ." Depress the brake pedal , the pedal should first be able to feel the tiny free travel ( in line with the requirements of the various models ) , free travel should be between 6 ~ 20mm. Continue to depress the pedal, the pedal should be stepped significant resistance until it stops . If the soft pedal down , there is no significant resistance , indicating a faulty brake system should be repaired ; If the pedal is pressed , the first pedal is very low, while the second leg but returned to normal, but the pedal is pressed firmly there are traces of flexibility , it means that there is an air brake lines , brake hydraulic lines should be excluded in the air. When the brake pedal in the end , the brake pedal should maintain a certain distance between the floor and the cab of the vehicle shall comply with the requirements of the distance . Distance is too small , indicating that the wheel brake shoe clearance is too large , you should adjust the wheel brake shoe clearance. STEP3: Check the brake system for leaks. Check the technical condition of the braking system , eliminate all loose joints , oil spills or leakage phenomenon. STEP4: Check the parking state. After starting the engine , a few minutes after the engine is running , the hydraulic pressure ( including vacuum booster type ) braking system , if a normal response to the brake pedal , the piping system is normal . STEP5: Check the running state. Start the engine , release the hand brake , making the car to 20 ~ 30km / h speed driving, the brake pedal on a dry flat surface, and the rapid deceleration of the car should stop , and no deviation phenomenon . After the car brake , release the brake pedal and when to continue driving , you should be able to start-up and running smoothly , but when in motion does not move the steering wheel, the car should keep straight without deviation. When the distance ( do not step on the brake ) , the parking brake drum inspection ( brake disc cartridge brake pads ) temperature cars with a period , the temperature should normally not hot . |
