Тормоз переднего моста FAW: Критический анализ 32 Основные компоненты (Саморегулирующийся)

Welcome to this critical technical analysis of the Тормоз переднего моста FAW (Сборка 544). This is the complete, S-Cam, “self-adjusting” drum brake assembly for the front steer axle of the FAW Jiefang CA4251P66K24T1A3E5 6×4 diesel semi-trailer tractor. This assembly is the primary “service brake” responsible for stopping the vehicle.

The Тормоз переднего моста FAW is a heavy-duty pneumatic “logic” system. Its function is to convert high-pressure air from the ‘Front brake air chamber’ (3519110-64А) into immense mechanical stopping force. This is achieved through the rotational logic of the ‘S-Cam’ and the ‘Front left/right slack adjuster assembly’ (3501205D242-C00).

This in-depth guide is an essential resource for professional brake technicians and fleet managers. We will deconstruct the entire Тормоз переднего моста FAW system into its 32 serviceable components, including the S-cams, slack adjusters, brake shoes, support brackets, and the critical springs and rollers that ensure fail-safe operation. Understanding this Тормоз переднего моста FAW is key to vehicle safety.

Core “Logic” 1: The S-Cam Actuation System

The heart of the Тормоз переднего моста FAW‘s actuation “logic” is the “S-Cam.” This assembly includes the ‘Front left cam’ (3501015D242) and ‘Front right cam’ (3501020D242). This is a simple, robust, and incredibly powerful mechanism.

This component is a solid, S-shaped, forged steel “cam” that is part of a shaft. This shaft passes through the ‘Front left/right axle head bracket’ (3501127С242 / 3501128С242) and is supported by ‘Bushing-brake cam shaft’ (3501153-А0С). On the outside of the Тормоз переднего моста FAW, this shaft is splined to the ‘Slack adjuster assembly’ (3501205D242-C00).

Here is the “logic” of the Тормоз переднего моста FAW in action:

1. The driver presses the brake pedal, sending air to the ‘Front brake air chamber’ (3519110-64А).
2. The air chamber pushes a rod, which rotates the ‘Slack adjuster’.
3. The ‘Slack adjuster’ rotates the S-cam shaft.
4. The “С” profile of the cam rotates between the two ‘Front brake shoe rollers’ (3501151С242).
5. As the “high spot” of the “С” rotates, it acts as a wedge, forcing the two ‘Front brake shoe’ (3501082-4Э) assemblies apart with immense mechanical advantage.
6. This forces the ‘Brake lining’ (3501086-4Э) into the ‘Front brake drum’ (see Assembly 523), creating the friction that stops the truck.

When the driver releases the pedal, air is vented, and the ‘Return springs’ (3501436-4Э, 3502392BA2T) snap the shoes back together, forcing the S-cam to rotate back to its “home” position. This simple, powerful logic is the standard for heavy-duty air brakes.

Core “Logic” 2: The Self-Adjusting System (3501205D242-C00)

The most important safety “logic” of the Тормоз переднего моста FAW is its “self-adjusting” capability. This is the function of the ‘Front left/right slack adjuster assembly’ (3501205D242-C00, 3501210D242-C00).

As the ‘Brake lining’ (3501086-4Э) wears down, а “gap” between the shoe and the drum increases. This means the S-cam must rotate further and further to make contact. Этот “slack” results in a long, “spongy” pedal travel and dangerously slow brake application.

This ‘Slack adjuster’ assembly is the solution. It is an “intelligent” lever. It contains an internal one-way clutch mechanism. During normal braking, it acts as a solid lever. Однако, if the travel (а “slack”) becomes too great, the internal mechanism “clicks” one notch on its return stroke. Этот “click” slightly rotates the resting position of the S-cam shaft, permanently “adjusting” а “home” position of the brake shoes to be closer to the drum.

Этот “self-adjusting” logic is a critical safety feature that ensures the Тормоз переднего моста FAW is always in perfect adjustment, providing a firm pedal and immediate stopping power. A failed slack adjuster (one that is seized or has a broken spring) is a critical fault that will cause the brakes on that wheel to either drag (if stuck “на”) or not apply (if stuck “off”). This component is a key part of the Тормоз переднего моста FAW system.

The Foundation: Brackets, Shoes, and Springs

The entire Тормоз переднего моста FAW assembly must be mounted to the non-rotating steering knuckle. Этот “foundation” is provided by the ‘Front left brake support’ (3501021С242), ‘Front right brake support’ (3501022С242), and the ‘Front left/right axle head bracket’ (3501127С242, 3501128С242). These heavy-duty steel brackets are the “anchor” for the entire system.

The ‘Front brake shoe’ (3501082-4Э) (two per side) and its ‘Brake lining’ (3501086-4Э) are the main friction components. The ‘Brake shoe roller’ (3501151С242) and ‘Roller shaft’ (3502394BA2T) are the low-friction “contact points” that the S-cam pushes against.

The “fail-safe” logic of the Тормоз переднего моста FAW is provided by the springs. The ‘Return spring’ (3502392BA2T) and ‘Return spring-front brake shoe’ (3501436-4Э) are high-tension springs that are constantly *pulling* the brake shoes *away* from the drum. The force of the S-cam must overcome this spring tension. The instant the driver releases the brake pedal, these springs snap the shoes back, immediately releasing the brake. A broken or weak return spring is a dangerous fault that will cause the Тормоз переднего моста FAW к “drag,” leading to overheating, brake fade, and potential fire.

FAW Front Axle Brake Parts List (1/2)

The following table provides the first part of the detailed breakdown for the Тормоз переднего моста FAW (544) diagram for the FAW CA4251P66K24T1A3E5 tractor.

FAW Front Axle Brake Parts List (2/2)

This table details the remaining components for the Тормоз переднего моста FAW (544) диаграмма.

Technical Specifications and Assembly Context

The specifications for the Тормоз переднего моста FAW are defined by its function as a heavy-duty, S-Cam, self-adjusting air brake. The Тормоз переднего моста FAW is a primary safety system.