FAW Air Brake Module Assembly: A Comprehensive Focus on 17 Critical Components

Welcome to this comprehensive technical guide on the FAW Air Brake Module Assembly (Assembly 542). This is the complete, chassis-mounted pneumatic control and air storage system for the FAW Jiefang CA4251P66K24T1A3E5 6×4 diesel semi-trailer tractor. This assembly is the “power pack” for the truck’s entire braking system.

The FAW Air Brake Module Assembly is a “logic” system that integrates multiple components. Its function is to safely store the high-pressure air generated by the compressor in the ‘Air storage tank assembly’ (3513055-91W) and to house the vehicle’s batteries on a single, secure, chassis-mounted bracket.

This in-depth guide is an essential resource for professional chassis technicians and fleet managers. We will deconstruct the entire FAW Air Brake Module Assembly into its 17 serviceable component types, including the air tanks, the main ‘Air storage tank & battery bracket assy’ (3513800-91W), the ‘Drain valve’, and all the critical fittings and high-tensile fasteners that make this system safe and reliable.

Core Component: The ‘Air Storage Tank Assembly’ (3513055-91W)

The heart of the FAW Air Brake Module Assembly is the ‘Air storage tank assembly’ (3513055-91W), also known as the “air reservoir” or “air tank.” The parts list calls for two of these. These are heavy-duty, steel-walled cylinders designed to safely store compressed air at pressures exceeding 120 PSI (8.3 bar).

This is the “power supply” for the entire brake system. The “logic” of a pneumatic FAW Air Brake Module Assembly is to have a large volume of pre-compressed air ready at all times. When the driver hits the brake pedal, it’s not their foot pressure doing the work; they are simply opening a valve that releases this massive, stored energy to the brake chambers.

These tanks must be in perfect condition. Over time, moisture from the air system can settle in the bottom, causing internal rust. This rust can flake off, travel down the FAW Air Brake Module Assembly, and clog the sensitive brake valves. A heavily-rusted tank can, in a worst-case scenario, rupture under pressure, leading to a catastrophic and total loss of all braking power.

The “Logic”: Integrated Bracket (3513800-91W) and Drain Valves (3513100-1500)

The “logic” of the FAW Air Brake Module Assembly is its integrated design. The ‘Air storage tank & battery bracket assy’ (3513800-91W) is the main “skeleton” of the assembly. This is a complex, heavy-duty fabricated steel bracket that serves two purposes:

• It acts as the “cradle” that holds the two ‘Air storage tank assembly’ (3513055-91W) units, securing them to the chassis frame with ‘Tank strap assembly’ (3513095-91W).
• It also provides the housing and support for the truck’s main batteries via the ‘Battery cover plate’ (3513801-91W).

This “logic” of combining the air tanks and battery box into one module saves space on the chassis rail, a critical commodity on a modern tractor. The ‘Air storage tank bracket’ (3513081-91W) units are the individual mounts that are part of this main assembly.

The most important service “logic” on the FAW Air Brake Module Assembly is the ‘Drain valve assembly’ (3513100-1500). There are two of these, one for each tank. Air from the compressor inevitably contains some moisture. This moisture condenses and settles at the bottom of the air tanks. The “logic” of the drain valve is to provide a simple, manual way to “drain” this corrosive water from the system daily, protecting the entire FAW Air Brake Module Assembly from internal rust and freeze-up in cold weather.

Fittings and Service Ports

The FAW Air Brake Module Assembly is a sealed, high-pressure system that relies on a complex array of “fittings” (grommets) and service ports. The parts list calls for a large quantity of these:

• ‘Grommet (M22) with sealing ring assy’ (3513410-1500) – 4 units
• ‘Grommet (M16) with sealing ring assy’ (3506410-1500) – 1 unit
• ‘Plug chamber (M16) with sealing ring assy’ (3506415-1500) – 1 unit

These are the “ports” where the high-pressure nylon air lines (from Assembly 539) connect to the air tanks. The “grommet” design is a “push-to-connect” fitting, sealed with ‘Special-shaped sealing rings’ (3513403-1500, 3506403-1500) and held in place by ‘Circlips’ (3513407-1500, 3506407-1500). This “logic” allows for a fast, reliable, and field-serviceable connection. A failure of one of these O-rings or ‘Gasket rings’ (3513839-91W) will result in a “slow leak,” causing the air compressor to cycle constantly and potentially draining the FAW Air Brake Module Assembly overnight.

The ‘Quick-connect test connector’ (T833) is a diagnostic “logic” port. It allows a technician to quickly connect a pressure gauge to the FAW Air Brake Module Assembly to test the system pressure without having to disconnect a main line.

Critical Fasteners and Hardware

The FAW Air Brake Module Assembly holds hundreds of pounds of steel (tanks and batteries) and is subjected to constant road vibration. Its fastener system is critical to its safety and function.

**Chassis Mounts:** The main ‘Air storage tank & battery bracket assy’ (3513800-91W) is secured to the truck’s frame with four ‘Hex head flange lock nuts’ (CQ32614) and four ‘Hex flange bolts’ (Q1841445T). The “flange” and “lock nut” design is a “logic” choice to prevent loosening under vibration.

**Tank Mounts:** The ‘Air storage tank brackets’ (3513081-91W) are secured with ‘Hex head bolts’ (CQ1501025), ‘Hex nuts’ (CQ34010), and ‘Spring gaskets’ (Q40310). The ‘Tank strap assembly’ (3513095-91W) is tightened with ‘Inner hex socket head cap screws’ (CQ2180870Q).

**Battery Mounts:** The ‘Battery cover plate’ (3513801-91W) is secured by ‘Locking clamps’ (3513837-91W, 3513837-2000), which are locked down with ‘Cotter pins’ (3513839-91W). This “pin” logic is a quick-release, yet positive-locking, mechanism that allows for battery service while ensuring the heavy batteries cannot escape. This entire hardware set is essential to the integrity of the FAW Air Brake Module Assembly.

FAW Air Brake Module Assembly Parts List

The following table provides the complete, detailed breakdown of all 17 component types identified in the ‘Air Brake Module Assembly’ (542) diagram for the FAW CA4251P66K24T1A3E5 tractor.

Technical Specifications and Assembly Context

The specifications for the FAW Air Brake Module Assembly are defined by its function as an integrated, chassis-mounted air storage and battery housing. The FAW Air Brake Module Assembly is a critical, space-saving component.