FAW Fuel Coarse Filter: A Comprehensive Guide to Its 9 Key Components

Welcome to this comprehensive technical guide on the FAW Fuel Coarse Filter (Part No. 1105010-2007-C00), the engine’s critical first line of defense for the FAW Jiefang CA4251P66K24T1A3E5 6×4 diesel semi-trailer tractor.

The FAW Fuel Coarse Filter is a dual-function assembly, often called a fuel/water separator. Its primary job is to remove large contaminants (dirt, rust, algae) from the fuel tank, a process known as “coarse” filtration. Its second, and arguably more critical, function is to separate and remove all free and emulsified water from the fuel.

This guide is an essential resource for professional technicians and parts specialists. We will deconstruct the entire FAW Fuel Coarse Filter assembly, including its main housing, the replaceable filter element, the integrated water-in-fuel sensor, and all mounting hardware, down to the smallest serviceable unit.

Core Component: The Filter Assembly (1105010-2007-C00)

The main component, Mark 1, is the ‘Fuel Filter Assembly’ (1105010-2007-C00). This is the complete FAW Fuel Coarse Filter unit. It is comprised of three main sub-assemblies that work together.

**1. Main Housing (1105020-2007):** The ‘Fuel Filter Main Housing Assembly’ is the permanent “head” of the system. This is a precision-cast aluminum component that mounts to the chassis via brackets. It contains the fuel inlet and outlet ports, the threaded mount for the filter element, and the internal passages for the fuel. The entire FAW Fuel Coarse Filter system is built upon this housing.

**2. Filter Element (1105050-2007):** The ‘Fuel Filter Element Assembly’ is the serviceable “cartridge.” This is the part that is replaced during maintenance. This spin-on canister contains the “coarse” filter media, which is a high-flow, high-capacity media designed to trap large particles (e.g., 30-100 microns). Its job is to protect the *next* filter in the system (the “fine filter”) from being overwhelmed by large contaminants like rust flakes or algae, thus extending its life. This element is the “workhorse” of the FAW Fuel Coarse Filter.

The Critical Logic: Water Separation (Coalescing)

The most important function of the FAW Fuel Coarse Filter is not just filtration, but water separation. Diesel fuel is easily contaminated with water, which is catastrophic for a high-pressure common rail (HPCR) injection system. Water causes rust and corrosion in the injectors and can flash-boil from the pressure, destroying the injector tips.

The media inside the FAW Fuel Coarse Filter element (1105050-2007) is “hydrophobic.” This means it repels water. As fuel flows through the media, the microscopic, emulsified water droplets are forced to “coalesce”—they merge into larger, heavier droplets.

These heavy water droplets, which are denser than diesel fuel, fall out of the fuel flow and collect in a “sump” or “bowl” at the bottom of the FAW Fuel Coarse Filter canister. This collected water can then be drained by the operator. This water separation logic is the primary purpose of the FAW Fuel Coarse Filter, acting as the gatekeeper for the entire fuel system. A failure in this coalescing function will lead to the rapid and extremely expensive failure of the HPCR pump and all six injectors.

The Warning System: Water Level Sensor (1105150C50A)

The third sub-assembly of the FAW Fuel Coarse Filter is the ‘Water Level Sensor Assembly’ (1105150C50A). This is the electronic “watchdog” for the system. It is a sensor, or “probe,” that threads into the bottom of the filter bowl where the water collects.

This sensor typically has two small metal electrodes. As water fills the bowl, it eventually rises to the level of these probes. Since water is conductive (while diesel fuel is not), it completes an electrical circuit between the two probes. This sends a signal to the ECU, which then illuminates the “Water in Fuel” warning light on the dashboard.

This signal is a non-negotiable service warning. It tells the driver or technician to *immediately* stop and drain the water from the FAW Fuel Coarse Filter bowl (usually via a small petcock at the bottom). If this warning is ignored, the bowl will fill completely, and the FAW Fuel Coarse Filter will lose its ability to separate water. From that point on, all incoming water will be pulled directly into the engine, leading to catastrophic damage. The proper function of this sensor is therefore critical to the FAW Fuel Coarse Filter‘s logic.

The Mounting System: Brackets and Hardware

The entire FAW Fuel Coarse Filter assembly is a heavy component, especially when full of fuel. It must be rigidly mounted to the truck’s chassis frame rail to protect it from the engine’s vibration. This is the job of the two ‘Fuel Coarse Filter Bracket’ (1105121-2007) units.

These two brackets form a secure “shelf” or “cage” that bolts to the chassis. The ‘Fuel Filter Main Housing Assembly’ (1105020-2007) is then mounted to these brackets. The hardware listed is specifically for this dual-mounting purpose.

**Bracket-to-Chassis:** The two ‘Hex head bolts’ (CQ1501445), two ‘Spring gaskets’ (Q40314), and four ‘Hex nuts’ (CQ34012) are used. This suggests the bolts pass through the bracket, then the chassis rail, and are secured on the opposite side with a spring washer (to prevent loosening) and two nuts (the second acting as a “jam nut” to lock the first). This is a heavy-duty, vibration-proof mounting method for the FAW Fuel Coarse Filter brackets.

**Housing-to-Bracket:** The two ‘Combination Bolt’ (CQ1421245) and two ‘Combination Bolt’ (CQ1461250) units are then used to secure the FAW Fuel Coarse Filter housing to the brackets. “Combination bolts” have pre-installed, captive spring washers, making them ideal for high-vibration areas where dropping a washer is not an option. This robust hardware system ensures the FAW Fuel Coarse Filter remains stable.

FAW Fuel Coarse Filter Parts List

The following table provides the complete, detailed breakdown of all 7 primary components and sub-assemblies for the FAW Fuel Coarse Filter diagram, as specified for the FAW CA4251P66K24T1A3E5 tractor. Servicing the FAW Fuel Coarse Filter (1105050-2007) is a critical, regular maintenance task.

Technical Specifications and Assembly Context

The specifications for the FAW Fuel Coarse Filter are defined by its dual function as a particle filter and water separator. The entire FAW Fuel Coarse Filter system is the first line of defense for the fuel system.