Common faults and maintenance of semi-trailer – brake failure

November 12 20:48 2024

 How to determine if there is a braking risk for a large semi-trailer

1. Observe the wear of brake pads and brake discs. If the wear is severe, there may be a risk.

2. Check if there is any oil leakage or insufficient air pressure in the brake system.

3. When braking, feel whether the steering wheel is deflected, whether the vehicle is drifting or shaking.

4. After releasing the brake pedal, check if the pedal can be raised independently and without resistance.

5. After starting the vehicle, check if the braking force can be provided immediately.

6. Listen for any abnormal noise when braking.

 Fault manifestations and causes

1. Partial braking: When applying the brake, the steering wheel will deflect to one side due to uneven force from the left and right brake cylinders of the braking system.

2. Brake does not return to its original position: When releasing the brake pedal, the pedal cannot rise independently without resistance, which may be due to damage to the return spring, brake caliper, missing brake fluid, or oil leakage at the brake cylinder, pipelines, and joints.

3. Shaking during braking: It often occurs on old cars, where the surface is uneven or severely worn due to uneven brake drums or brake discs. New cars may have brake drums or brake discs that are of poor quality, or deformation caused by prolonged and forceful braking.

4. Unable to brake immediately after starting: The vehicle cannot provide braking force immediately after starting and needs to be warmed up for a period of time, possibly due to pressure loss in the pressure transmission pipeline. It is necessary to check whether the interface between the vacuum assist pipe of the master cylinder and the engine is cracked or loose.

5. Brake deviation: When the brake is applied, the vehicle cannot decelerate in a straight line, but deviates to one side, which may be caused by the expansion of one piston in the master cylinder or uneven brake wear.

6. Insufficient air pressure or dragging brake: If the air pressure remains below 0.7MPa for a long time or there is obvious dragging brake phenomenon during driving, it is necessary to eliminate the tractor fault or check the source of air leakage.

7. Unable to start after parking: The trailer cannot start after parking and keeps stuck, which may be due to circuit problems or the parking brake not being released, or there may be mechanical faults in the axle.

8. Weakened braking force: Weakened braking force and extended braking distance may be due to severe wear of brake pads, which need to be replaced in a timely manner.

9. Brake noise: A harsh creaking or sharp friction sound is produced during braking, which may be caused by poor contact between the brake pad surface and the brake disc. It is necessary to check whether there are foreign objects or dirt accumulation on the brake pads.

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 The price of brake malfunction repair (within the reference range of China)The repair price for different brake problems varies depending on various factors such as vehicle model, brake system type, location, and the level of repair shop. The following is a rough range of repair prices provided based on common brake problems, for reference only:

1. Brake pad replacementPrice range: For large semi trailers, the price for replacing brake pads usually ranges from several hundred to several thousand yuan, depending on the material, brand, and repair shop’s charging standards of the brake pads. For example, some high-quality brake pads may be more expensive, and some professional repair shops may also charge higher labor costs.Attention: Brake pads are one of the most important components in the brake system, and their quality and performance directly affect the braking effect of the vehicle. Therefore, when replacing brake pads, reliable products should be selected and the correct installation steps should be followed.

2. Brake disc/drum replacement or repairPrice range: The replacement or repair price of brake discs/drums also varies depending on the model and repair shop. Generally speaking, the replacement price of brake discs/drums is relatively high, which may require thousands or even more yuan. The repair price is relatively low, but it still needs to be determined based on the degree of damage.Attention: The brake disc/drum is a critical component in the brake system, and its surface condition directly affects the braking effect. If the brake disc/drum experiences severe wear, cracks, or deformation, it should be replaced or repaired in a timely manner.

3. Brake fluid replacementPrice range: The price for replacing brake fluid is usually relatively fixed, usually around a few hundred yuan. This includes the purchase cost of brake fluid and the labor cost required during the replacement process.Attention: Brake fluid is the transmission medium in the brake system, and its performance directly affects the response speed and braking effect of the brake system. Therefore, regular replacement of brake fluid is an important measure to maintain stable performance of the brake system.

4. Cleaning and maintenance of brake systemPrice range: The price for cleaning and maintaining the brake system varies depending on the project and repair shop. Generally speaking, comprehensive maintenance items including brake pad cleaning, brake disc/drum grinding, brake fluid inspection, etc. may cost hundreds to thousands of yuan.Attention: Cleaning and maintenance of the brake system are of great significance for maintaining its good performance and extending its service life. It is recommended that car owners regularly visit a professional repair shop for a comprehensive inspection and maintenance of the brake system.

5. Repair of other brake issuesPrice range: For other brake problems such as brake cylinder failure, brake master cylinder failure, etc., the repair price varies depending on the type and severity of the fault. Generally speaking, the repair cost for these faults may be higher, requiring thousands or even more yuan.

Attention: For such complex braking problems, it is recommended that car owners promptly go to a professional repair shop for inspection and maintenance. Avoid disassembling or repairing on your own to prevent greater damage or safety hazards.

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Please note that the above price range is for reference only. The specific price will depend on the vehicle model, location, and the actual situation of the repair shop. When repairing the brake system, it is necessary to choose a repair shop with professional qualifications and good reputation to ensure the quality of repair and driving safety. Emergency handling methods for brake faults encountered during drivingWhen encountering emergency brake failure during the operation of a large semi-trailer, the following steps can be taken to handle it:

1. Attempt predictive braking: When driving down long or steep slopes, regardless of the situation, the brake should be applied to test its performance and gain time to control the vehicle speed in case of possible brake failure.

2. Control direction and shift to low gear: Control direction according to road conditions and vehicle speed, quickly shift from high gear to low gear, and use the engine’s traction resistance to reduce vehicle speed.

3. Moderate use of handbrake: While shifting to low gear, use the handbrake moderately, but be careful not to pull it too tightly or too slowly to prevent damage to the transmission components or wear and burn of the brake disc.

4. Use obstacles to slow down: If the vehicle is still in motion and cannot be controlled by its own mechanism, it should decisively use natural obstacles on the roadside (such as rocks, trees, etc.) to create resistance for the car and forcefully stop to escape danger. Be careful to choose solid obstacles that do not pose greater danger.

5. Turn on the warning light and prompt: promptly turn on the hazard warning flash, and sound the horn or shout and wave to alert surrounding vehicles and pedestrians to avoid.

6. Find a safe haven area: If an emergency shelter is designed on the road, vehicles can be driven towards the shelter for safety.

Please note that these measures are only emergency response measures and cannot fully guarantee safety. Usually, it is necessary to strengthen the inspection and maintenance of the brake system to ensure that the vehicle is in good condition and avoid dangerous situations such as brake failure. For the maintenance of the brake system

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When maintaining the brake system of a large semi-trailer, the following points should be noted:

1. Regularly inspect brake components, including the wear of brake drums, the thickness of brake shoes, and whether there are leaks in brake oil pipes, to ensure the integrity of the brake system.

2. Adjust the brake system: Regularly adjust the stroke of the brake arm and the length of the brake cylinder push rod to ensure the sensitivity and stability of the brake. At the same time, check and adjust the gap between the brake shoes and the brake drum to ensure that it is within the specified range.

3. Keep the brake system clean: Regularly clean the brake system to prevent dust, oil stains, and other impurities from entering and affecting brake performance.

4. Pay attention to the quality of brake fluid: Regularly replace brake fluid to ensure good performance and normal fluid level. The amount of brake fluid should be moderate, and a rapid decrease may be a signal of a brake system malfunction.

5. Proper use of brakes: In daily driving, avoid sudden braking and prolonged continuous braking to reduce the wear and tear of the braking system.

Following these maintenance measures can ensure the good operation of the braking system of large semi trailers and improve driving safety.

Shandong Shodailer Automobile Manufacturing Co. , Ltd. 

Our company is committed to creating lightweight trailer products that are extremely durable and safe by introducing advanced design concepts and production processes from both domestic and international sources, and relying on independent research and development. At present, the company has hundreds of employees with over ten years of industry experience, dozens of modern standard workshops and assembly lines, and more than 30 independent research and development teams,The core management team has many years of experience in enterprise operation management and market development in the trailer industry. Through continuous innovation and optimization of vehicle models, we have obtained multiple national patents and have successively passed the national 3C certification and ISO9001 international quality management system certification. We have been awarded honorary titles such as China’s 3A level unit for quality, reputation, and service by the China Integrity Enterprise Product Quality Supervision Center.At present, the products are exported to more than 30 countries, and are widely praised in Southeast Asian countries such as Vietnam, the Philippines, Thailand, Indonesia, African countries such as Tanzania, Sudan, Ghana, Cameroon, South Africa, Nigeria, as well as Russia, Kazakhstan and other countries. We have a complete service process and team, and have already opened branch factories abroad. We offer warehouse visits, spot inspections, fleet maintenance, and remote guidance services. You are welcome to contact us for inquiries about buying a semi trailer

If you want to inquire about relevant product information, you can directly send an inquiry on our website homepage. You can also call this number to inquire +8619153910141. Looking forward to your visit

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Company Name: Shandong Shodailer Automobile Manufacturing Co., Ltd.
Email: Send Email
Phone: +86 0539-4567006
Address:Wenhe 2nd Road, Mengyin Development Zone
City: Linyi
State: Shandong
Country: China
Website: https://www.shodailer.com/