Dongfeng GX Rear right disc brake and chamber assembly 3502425-H18A0

The assembly features a one-piece integrated structure that combines a hydraulic disc brake caliper with a dual-chamber air actuator (service brake chamber + parking brake chamber)—eliminating the need for separate mounting and reducing potential points of failure. The air chamber’s pushrod is directly connected to the brake caliper’s lever mechanism, creating a short, rigid force transmission path that minimizes energy loss. This design ensures rapid brake response (≤ 0.3 seconds from air pressure application to brake pad contact) and consistent braking force distribution across the rear right wheel. Additionally, the integrated layout optimizes space utilization on the rear axle, avoiding interference with other components (e.g., suspension arms, exhaust systems) while simplifying maintenance.

Brake Disc: Constructed from high-carbon cast iron (HT250) with a ventilated dual-layer design. The material’s high thermal conductivity (≥ 50 W/m·K) and heat capacity (≥ 500 J/kg·K) enable efficient dissipation of braking heat (up to 600°C), preventing thermal fade during heavy or continuous braking. The disc’s surface is precision-ground to a roughness of Ra ≤ 0.8μm, ensuring smooth contact with brake pads and reducing wear.

Brake Pads: Made of semi-metallic friction material (comprising iron powder, copper fiber, and resin binder) with a friction coefficient of 0.35-0.45 (stable across -30°C to 400°C). The pads feature a wear indicator groove—when the groove is worn down, it signals the need for replacement, preventing metal-to-metal contact that could damage the disc.

Air Chamber: Fabricated from high-strength aluminum alloy (ADC12) for the housing and nitrile rubber (NBR) for the diaphragm. The aluminum housing resists corrosion and reduces weight, while the NBR diaphragm withstands repeated air pressure cycles (100,000+ operations) without cracking or leakage. The chamber also includes a manual slack adjuster to compensate for brake pad wear, maintaining consistent pedal travel.

The integrated air chamber provides two critical braking functions for the Dongfeng GX:

Service Braking: The front (service) chamber is activated by air pressure from the vehicle’s brake pedal, pushing the pushrod to apply the brake pads against the disc—delivering the primary stopping force during normal driving. It is designed to handle frequent, light-to-moderate braking loads, with a maximum output force of 15-20 kN (depending on GX model).

Parking/Emergency Braking: The rear (parking) chamber uses a pre-loaded compression spring to apply constant force to the brake pads when the vehicle is parked or in an emergency (e.g., air pressure loss). The spring force is released only when air pressure is supplied (via the parking brake valve), ensuring reliable immobilization of the vehicle on slopes (up to 30° incline) and preventing rollaway risks. This dual-chamber design complies with global safety regulations for commercial vehicles, requiring independent parking and service brake systems

This rear right disc brake and chamber assembly meets international commercial vehicle braking standards, including China’s GB 7258 (Safety Technical Specifications for Motor Vehicles), ISO 4194 (Automotive disc brakes), and ECE R13-H (UN regulations for heavy-duty vehicle brakes). Each unit undergoes rigorous pre-shipment testing:

Braking Performance Test: Conducted on a dynamometer to verify stopping distance (≤ 15m at 50 km/h) and thermal fade resistance (friction coefficient decay ≤ 15% after 10 consecutive hard stops).

Air Tightness Test: Pressurizing the air chamber to 1.0 MPa and holding for 30 minutes—pressure drop must be ≤ 0.02 MPa, ensuring no leakage.

Durability Test: Simulating 500,000+ brake cycles (mimicking 300,000+ km of driving) to check for component wear, pad/disc compatibility, and spring fatigue.

Environmental Test: Exposing the assembly to salt spray (1,000 hours), high humidity (95% RH at 40°C for 500 hours), and extreme temperatures (-40°C to 80°C for 200 hours) to validate corrosion resistance and performance stability.

The assembly is backed by a manufacturer’s warranty (typically 24-36 months), providing customers with confidence in its reliability for Dongfeng GX’s heavy-duty operating conditions (e.g., long-haul transport, high-load cargo)