FAW Floor Blockage: The 7 Essential MSUs for a Quiet, Rust-Free Cab

Welcome to this essential guide on the FAW Floor Blockage assembly. This is the complete 30-piece kit of engineered seals, grommets, and plugs for the FAW Jiefang CA4251P66K24T1A3E5 6×4 tractor. These components are not cosmetic; they are a critical first-line defense for the cab’s integrity. Their core “logic” is to create a hermetic, “triple-threat” seal for the cab’s floor pan, protecting the driver and the vehicle from noise, water, and fumes.

The FAW Floor Blockage system is a foundational component of the cab’s Noise, Vibration, and Harshness (NVH) package. The “logic” of this kit is to permanently seal the various access and drainage holes left in the sheet metal during the manufacturing (stamping, e-coating) process. Leaving these holes open would allow a direct path for engine noise, road spray, and dangerous exhaust gases to enter the cab.

This in-depth guide is a vital resource for body shop technicians, collision specialists, and parts managers. We will deconstruct the entire FAW Floor Blockage kit into its 7 distinct Minimum Serviceable Unit (MSU) types. We will analyze the material science, the multi-functional sealing “logic,” and the specific location logic for each of the 30 pieces.

The “Triple-Seal” Logic: Noise, Water & Fume Barrier

The FAW Floor Blockage assembly is not about aesthetics; it is about “sealing logic.” A single missing plug can compromise the entire cab environment. This 30-piece kit provides three critical barrier functions.

1. Acoustic Sealing (NVH Logic):

The primary “logic” is to block noise. The cab sits directly over the engine, transmission, and road. A single un-plugged hole acts as a “sound leak,” allowing low-frequency engine drone and high-frequency tire/wind hiss to enter the cab. This noise dramatically increases driver fatigue.

These FAW Floor Blockage plugs are made from dense, heavy EPDM rubber. They function as “acoustic dampers,” a key part of the ‘Soundproofing Pad’ system (Assembly 623). They have the mass to block and reflect sound waves, ensuring the cab remains quiet.

2. Water & Corrosion Sealing Logic:

This is the “logic” of longevity. The front tires constantly spray water, mud, and corrosive road salt against the underside of the cab. If a plug is missing, this moisture is injected *under* the cab’s floor covering.

This trapped moisture saturates the sound deadening pads, which acts like a sponge against the bare metal floor. This is the #1 cause of cab floor rust-out, which rots the cab from the inside. A single missing FAW Floor Blockage plug can destroy a floor pan.

3. Fume & Air Sealing Logic:

This is the primary “safety logic.” The plugs on the firewall (‘Front Panel’) and transmission tunnel are a gas-tight seal. They prevent deadly, odorless Carbon Monoxide (CO) fumes from a potential exhaust leak from entering the driver’s breathing space.

This seal also stops drafts, dust, and hot/cold air. This “logic” is key to HVAC efficiency. By sealing these leaks, the FAW Floor Blockage kit ensures the A/C and heater can maintain temperature without running constantly, saving fuel.

Material & Design Logic: EPDM Rubber

The FAW Floor Blockage plugs are not made from simple plastic. They are high-tech MSUs made from a specific material: EPDM (Ethylene Propylene Diene Monomer) rubber.

Material Logic: EPDM is the “logic” choice for this hostile environment.

• Temperature Resistance: It will not get brittle and crack at -40°C, and it will not melt or get soft at +120°C from exhaust heat.
• Chemical Resistance: It is highly resistant to water, road salt, oil, diesel fuel, and brake fluid.
• Ozone/UV Resistance: The plugs on the firewall are exposed to engine bay ozone and UV light. EPDM will not crack or dry-rot like natural rubber.

Design Logic: These MSUs are designed for a one-way, “push-in” installation. Each plug features a deep “groove” around its circumference. The “logic” is that the plug is pushed through the sheet metal hole until the metal “snaps” into this groove. This creates a 360-degree, “interference fit” that is both waterproof and vibration-proof, ensuring the plug *cannot* be shaken loose.

Deconstructing the 7 MSU Types (The “Longer” Module)

The FAW Floor Blockage kit contains 7 distinct part numbers (MSUs), totaling 30 pieces. This “logic” of having so many types is for precision. Each plug is precision-molded to fit a *specific* hole’s shape and diameter.

MSU 7: Firewall Plugs (Qty 2)

The ‘Round plug C-front panel’ (5302808-A01) is designed for the “front panel” (firewall). These two plugs seal holes in the vertical wall separating the driver from the engine.

MSUs 1-6: Floor Pan Plugs (Qty 28)

These 28 plugs are the main components of the FAW Floor Blockage kit, and they seal the horizontal floor of the cab. They are grouped by shape.

Round Plugs (MSUs 1, 4, 5):

• ‘Hole plug B’ (5109566-A95) – Qty 2
• ‘Round plug D-floor’ (5109614-A01) – Qty 2
• ‘Round plug B-floor’ (5109617-A01) – Qty 2

The “logic” of these 6 round plugs is to seal circular holes, likely from manufacturing alignment pins or small drainage holes. The “B,” “C,” and “D” designations refer to specific, non-interchangeable diameters.

Oblong Plugs (MSUs 2, 3, 6):

• ‘Oblong plug B-floor’ (5109612-A01) – Qty 12
• ‘Oblong plug D-floor’ (5109613-A01) – Qty 9
• ‘Oblong plug C-floor’ (5109619-A01) – Qty 1

The “logic” of these 22 oblong plugs is to seal the non-circular holes. The cab floor is stamped with ribs for strength. The “valleys” of these ribs are a common place for oblong drainage and access holes, and these MSUs are molded to fit them perfectly.

Each of these 7 part numbers is a distinct MSU. When servicing a cab (e.g., replacing the ‘Floor Insulation Underlay’), it is critical to inspect for any missing or damaged plugs. Each missing plug must be replaced with the *exact* part number to ensure a perfect “interference fit” seal.

FAW Floor Blockage Parts List

The following table provides the complete, detailed breakdown of all 7 component types identified in the FAW Floor Blockage assembly for the FAW CA4251P66K24T1A3E5 tractor.

Technical Specifications and Assembly Context

The specifications for the FAW Floor Blockage kit are defined by its function as a complete sealing system for the cab-in-white. All components are critical MSUs for cab integrity.