FAW Fuel Oil Heater Logic Assembly: Une ventilation complète de 17 Éléments essentiels

Bienvenue dans ce guide technique complet sur le FAW Fuel Oil Heater Logic Assembly (Partie no. 1312010-74T), a critical system for all-weather reliability on the FAW Jiefang CA4251P66K24T1A3E5 6×4 tracteur semi-remorque diesel. This assembly is the engine’s primary defense against cold-weather fuel gelling.

Le FAW Fuel Oil Heater Logic Assembly is a sophisticated heat-exchanger system. C'est “logique” is to use hot engine coolant to heat the diesel fuel *before* it reaches the filters. This action prevents the paraffin wax in cold diesel from crystallizing (“gelling”), which would clog the fuel filters and starve the engine of fuel.

This guide is an essential resource for professional technicians and parts specialists. Nous déconstruirons l'ensemble FAW Fuel Oil Heater Logic Assembly dans son 17 composants réparables, including the main heater, the auxiliary electromagnetic pump, all coolant and fuel plumbing, and the mounting brackets.

Composant principal: The Fuel Heater Assembly (1312010-74T)

Le coeur du FAW Fuel Oil Heater Logic Assembly is the ‘Fuel Heater Assembly’ (1312010-74T). This is the main heat exchanger. C'est un “liquid-to-liquid” cooler, operating in reverse: it uses hot liquid (liquide de refroidissement) to heat a cold liquid (carburant).

This unit is typically a “plate-style” ou “shell-and-tube” exchanger. Hot engine coolant is forced through one set of internal passages, while cold diesel fuel from the tank is forced through a separate, alternating set of passages. The two fluids never touch, but the heat from the 80-90°C coolant is efficiently transferred through the thin metal plates to the sub-zero fuel.

This action raises the fuel temperature well above its “cloud point,” ensuring the paraffin wax stays in a liquid state. A failure of this FAW Fuel Oil Heater Logic Assembly cœur (Par exemple, an internal leak) is catastrophic. It can force high-pressure coolant into the fuel system, contaminating the injectors, or force diesel fuel into the cooling system, destroying all rubber hoses and seals. This makes the integrity of the FAW Fuel Oil Heater Logic Assembly paramount.

The Coolant “Piping” Circuit (1312035-74T)

Le FAW Fuel Oil Heater Logic Assembly cannot create heat; it can only transfer it. Le “tuyauterie” components are responsible for tapping into the engine’s main cooling system to acquire this heat. This circuit includes:

• ‘Fuel Heater Inlet Water Hose’ (1312038-74T)
• ‘Fuel Heater Outlet Water Hose’ (1312041-74T)
• ‘Fuel Heater Inlet/Outlet Steel Pipe Assembly’ (1312035-74T)
• ‘Return Water Hose’ (1312031-74T)

This system works by tapping hot coolant from a high-temperature point (like the thermostat housing) and routing it through the ‘Inlet Water Hose’ to the ‘Fuel Heater Assembly’. The ‘Steel Pipe Assembly’ provides a rigid, protected path along the chassis or engine. After the coolant has transferred its heat, the now-cooler fluid is sent back to the low-pressure side of the water pump via the ‘Outlet Water Hose’ and ‘Return Water Hose’. This continuous circulation is the “logique” de la FAW Fuel Oil Heater Logic Assembly.

These hoses are secured with ‘Worm Drive Hose Clamps’ (CQ67630B). A leak in any of these components will not only disable the FAW Fuel Oil Heater Logic Assembly, but will also cause the engine to lose coolant and overheat.

Le “Logique”: Electromagnetic Pump Assembly (1312020-74T)

The most advanced “logique” component of the FAW Fuel Oil Heater Logic Assembly is the ‘Electromagnetic Pump Assembly – with wire harness’ (1312020-74T). This is a critical auxiliary pump.

The engine’s main water pump is mechanical and only circulates coolant when the engine is running. This is a problem on a sub-zero “cold start.” Le FAW Fuel Oil Heater Logic Assembly needs to heat the fuel *before* the engine starts.

This ‘Electromagnetic Pump’ est la solution. When the driver turns the key to the “sur” position, the ECU activates this 24V electric pump. This pump immediately begins to circulate hot coolant from the (still warm from a block heater, or a Webasto-style heater) engine block, through the ‘Fuel Heater Assembly’, and back to the engine. Ce “pre-heat” cycle runs for 30-60 seconds *before* the starter is engaged, ensuring the fuel in the lines is already warm and de-gelled.

This pump, with its integrated ‘wire harness’, est le “cerveau” cela fait le FAW Fuel Oil Heater Logic Assembly an *active* system, not a passive one. It is likely routed via the ‘Three-way Joint Assembly’ (1312070-29T), which allows coolant to be sourced from either this pump or the main water pump, depending on whether the engine is on or off. Le FAW Fuel Oil Heater Logic Assembly‘s effectiveness depends entirely on this pump.

Supports, Scellés, and Fasteners

L'ensemble FAW Fuel Oil Heater Logic Assembly is a heavy, fluid-filled unit that must be protected from vibration. The ‘Fuel Heater Bracket Assembly’ (1312050-74T) is the main structural support. It bolts to the chassis, and the ‘Fuel Heater Assembly’ then bolts to this bracket.

Additional ‘Bracket’ (3406111-20V) units are used to secure the rigid ‘Steel Pipe Assembly’ (1312035-74T) and the ‘Electromagnetic Pump’, preventing them from fatiguing and cracking.

The system is sealed with the ‘Gasket ring’ (CQ72327) and ‘Joint’ (1312036-74T), which are single-use crush washers for the fluid connections. L'ensemble FAW Fuel Oil Heater Logic Assembly is fastened with a variety of high-grade hardware: « Boulons à bride hexagonale’ (Q1841435, Q1840820) and ‘Hex flange nuts’ (CQ39614, CQ39608). The ‘Plastic Zip Ties’ (T67420376) are used to secure the flexible hoses and wiring harness away from any hot or moving parts, completing the installation of the FAW Fuel Oil Heater Logic Assembly.

FAW Fuel Oil Heater Logic Assembly Parts List

Le tableau suivant fournit l'intégralité, ventilation détaillée de tous 17 components identified in the ‘Fuel Oil Heater Logic Assembly’ schéma du tracteur FAW CA4251P66K24T1A3E5. Ce FAW Fuel Oil Heater Logic Assembly is essential for cold-weather starting.

Spécifications techniques et contexte d'assemblage

Les spécifications pour le FAW Fuel Oil Heater Logic Assembly are defined by its function as an active, coolant-based heat exchanger. This entire FAW Fuel Oil Heater Logic Assembly is a key system for cold-weather operation.