Does the semi-trailer disc brake bridge need to be adjusted?

Disc brake trailer axle, also called disc axle, because of its brake metal block shape is disk/dish named. When braking, the brake disc is clamped by calipers, and the braking effect is produced by friction, which is used more in passenger cars.

However, with the introduction and implementation of the "Motor vehicle operation safety Technical conditions GB7258-2017", disc axles began to flourish on commercial vehicles, and some models, such as three-axis fence plates and warehouse grid semi-trailers, were also explicitly required to install disc axles.

The reason why the disc axle can become the official designated axle is because of three main reasons:

One is because the disc axle brake is more sensitive, more stable, and the heat dissipation effect is good, there is no need to install additional water sprinklers, and the thermal attenuation and water attenuation resistance are also better than the drum axle.

Second, in order to enhance the technical safety configuration of three-axis fence plate and warehouse grid semi-trailer, such vehicles have a relatively high application rate in the industry, but the technical safety level is relatively low, forcing the use of disc brake + empty suspension can improve the safety factor, but also reduce the overload phenomenon to a certain extent, after all, compared with the traditional configuration, empty suspension is not so dominant in heavy load.

Third, the disc axle in the domestic commercial vehicle application is relatively small, but in the trailer industry started and developed earlier in the Americas and Europe, its penetration rate is very high, the experience of the international market also provides a certain reference for the domestic.

However, compared with the traditional drum trailer axle, the disc brake axle price is generally high, most of which are concentrated between 6000-7000. Some brands with high premiums can reach 9000 or even 12000, of course, there is no shortage of 3000 or so cheaper.

Owners in the choice, do not simply look at the price. The processing of the axle is not only the cutting, welding and assembly of the steel pipe, but also requires a series of processes such as heat treatment molding, sandblasting, precision grinding, medium frequency induction, fatigue test, etc. The finer the process and the higher the technical level, the higher the safety of the product. I am afraid that the cost of these processing processes will add up to more than two or three thousand, and then count raw materials, hub bearings and other parts, which shows that a qualified axle processing cost is about how much.

If the owner is relatively well-off, you can choose big-name products, although the brand premium rate is relatively high, but the quality is relatively guaranteed. If the owner does not want to pay for the brand premium, you can choose those cost-effective positioning products, they enter the market earlier, the process, quality and technology are also trustworthy, the key price is relatively affordable, can help the owner to reduce the cost of the car. If there are conditions, it is still recommended to visit the factory to see whether the manufacturer has the corresponding production conditions.

The disc axle is simpler than the drum axle structure, and there is no designed adjusting arm, many owners believe that there is no adjusting arm, do not adjust the brake, which is inaccurate, although the disc brake bridge canceles the brake adjusting arm, there will be a gap under long-term use, so it is also necessary to manually adjust.

So, how to adjust the brake gap of the disc brake bridge?

1. Disc axle without brake pad wear sensor:

Release the brake, release the brake, pull out the rubber plug;

Press the return spring with the hex wrench, turn the lock counterclockwise until the brake liner is close to the brake disc;

Press the return spring with the hex wrench, and then rotate clockwise until you hear 3-4 sounds of "da";

Push the brake caliper slider with axial force to check whether the return is smooth;

After adjustment, install the rubber plug.

2. Disc trailer axle with brake pad wear sensor:

Release the brake, release the brake, remove the wear sensor;

Remove butterfly pin and washer;

Remove the pin, positioning spring and positioning plate;

Unplug the rubber plug;

Press the return spring with the hex wrench, turn the lock counterclockwise until the brake liner is close to the brake disc;

Press the return spring with the hex wrench, and then rotate clockwise until you hear 3-4 sounds "click";

After the adjustment, install the rubber plug, install the positioning plate, positioning spring and pin;

Install washers and butterfly pins;

Push the brake caliper slider with axial force to check whether the return is smooth;

Install a wear sensor.

The above are two common different configuration of disc axle brake clearance adjustment methods for your reference. Owners can carefully read the instruction manual of the purchased axle and adjust it in turn according to its steps.