FAW J6P Water Pump: Deconstructing 21 Critical Parts for Flawless Thermal Management

Welcome to this expert deconstruction of the FAW J6P Water Pump (Main Assy P/N 1307010-36D). This is the “heart” of the engine cooling system for the FAW Jiefang CA3250P66K2L1T1E 6×4 dump truck.

This is not a single part, but a complete “Logic Assembly” of 21 component types (part of the larger Chapter 27 Thermal Group). Its “logic” is to be a high-volume, belt-driven centrifugal pump that provides the *one thing* a heavy-duty diesel needs to survive: continuous, high-volume coolant flow.

The “Circulation Logic” of this FAW J6P Water Pump is its most critical function. It is the “muscle” of the thermal management system. It must circulate 30-40 liters of coolant through the entire engine and radiator, multiple times per minute, to pull heat *away* from the cylinder head and block. A failure here is not a minor issue; a loss of coolant flow (from a snapped belt or failed internal bearing) will cause the engine to overheat and seize *in minutes*.

This technical guide is essential for fleet technicians and engine specialists. We will deconstruct the entire component group associated with the FAW J6P Water Pump. We will analyze the “Centrifugal Pump Logic” (the pump assembly itself), the “Coolant Conditioning Logic” (the integrated water filter system), the “Plumbing & Flow Logic” (the inlet and bypass pipes), and the “Sealing & Fastener Logic” (the gaskets and bolts) that create a high-pressure, leak-proof FAW J6P Water Pump system.

Core 1: The “Centrifugal Pump” Logic (Components 11, 26, 28)

This group represents the “heart” of the cooling system. While the Thermostat (Chapter 27A) is the “brain,” this FAW J6P Water Pump is the “muscle.”

1. Component: ‘Water pump assy’ (1307010-36D)
This (Comp 26) is the “Centrifugal Flow Logic.” This is a high-volume, relatively low-pressure pump that is belt-driven from the engine’s front-end accessory drive. Its “logic” is simple: an internal, multi-bladed “impeller” (driven by the belt pulley) spins at high speed. It doesn’t “suck” water in; it “slings” it outwards by centrifugal force. This creates a low-pressure void at its center (the “inlet”) that draws coolant in, and a high-pressure zone at its edge (the “outlet”) that pushes coolant into the engine block. This is the core of the FAW J6P Water Pump.

2. The “Mechanical Seal Logic” (Internal to Comp 26)
The most critical part of the FAW J6P Water Pump is its internal seal. The pump shaft (which holds the pulley on the outside and the impeller on the inside) must pass *through* the pump housing. A “mechanical seal” (a high-tech, spring-loaded, carbon-and-ceramic ring) is what prevents high-pressure coolant from leaking out. This seal is “water-lubricated.” When this seal eventually wears out from time and use, coolant will drip from a “weep hole” in the bottom of the pump casting. This “Weep Logic” is a built-in “failsafe indicator,” telling the technician the FAW J6P Water Pump must be replaced *before* the bearing fails completely and seizes.

3. Component: ‘Water pump seat’ (1307041-29D)
This (Comp 11) is the “Mounting Logic.” This is the heavy-duty, cast-iron “base” or “flange” that the ‘Water pump assy’ (Comp 26) bolts to. This ‘seat’ is then bolted directly to the engine block with its own gaskets (Comp 8). This “adapter logic” provides a rigid, stable foundation that will not flex under the high tension of the serpentine belt. The ‘Bolt – water pump’ (Comp 28) and nuts (Comp 29, 30) are the critical fasteners for this.

Core 2: The “Coolant Conditioning” Logic (Components 16, 17, 24)

This is a “logic” unique to heavy-duty engines. The system doesn’t just pump coolant; it “conditions” it. This is a critical support function of the FAW J6P Water Pump.

1. Component: ‘Water filter assy’ (1307020-29D)
This (Comp 17) is the “Conditioning Logic.” This is not just a particle filter. Its “logic” is to be a “Bypass Filter” that contains “Supplemental Coolant Additives” (SCAs). A small “bleed” of coolant constantly flows from the FAW J6P Water Pump circuit, passes through this spin-on filter, and returns to the system.

2. The “SCA Logic” (Cavitation Prevention)
This is the “why.” Heavy-duty diesel engines vibrate violently. This vibration creates tiny, imploding steam bubbles (a process called “cavitation”) on the *outside* of the “wet” cylinder liners. These implosions act like microscopic jackhammers, and they *will* eat holes through the liner, causing catastrophic engine failure. The “SCA Logic” of this filter is that it slowly *dissolves* chemicals (like nitrites) into the coolant. These chemicals “plate” the metal surfaces, forming a sacrificial, protective layer that “cushions” against these cavitation implosions. This filter’s “logic” is to *prevent* this, making it a critical component for engine longevity.

3. Component: ‘Water filter shut-off valve’ (1307017-29D)
This (Comp 24) is the “Serviceability Logic.” The ‘Water filter’ (Comp 17) is a regular service item that must be changed. This “shut-off valve” (a ball or gate valve) is installed *before* the filter. Its “logic” is to allow a technician to *stop* the flow of coolant *to the filter*, allowing it to be spun off and replaced *without* draining the entire 30-40L cooling system. This is a massive time- and cost-saving feature. The ‘Water filter connecting nut’ (Comp 16) is the fastener for the filter head.

Core 3: The “Plumbing & Flow” Logic (Pipes & Hoses)

This group represents all the “arteries” that connect to the FAW J6P Water Pump and direct the flow of coolant.

1. Component: ‘Water pump inlet pipe assy’ (1307050-29D)
This (Comp 14) is the “Main Suction Logic.” This is the large-diameter, pre-formed pipe that connects the “suction” (center) of the FAW J6P Water Pump to the “outlet” (bottom) of the main radiator. Its “logic” is to provide a high-flow, non-collapsing path for the “cold” coolant to enter the pump. It’s held on by ‘Hexagon flange bolts’ (Comp 15).

2. Component: ‘Water pump bypass pipe’ (1307032-29D)
This (Comp 9) is the “Warm-Up Logic.” This pipe connects the ‘Thermostat’ housing *back* to the “suction” side of the FAW J6P Water Pump. When the thermostat is *closed* (engine cold), this pipe is the *only* path for coolant to circulate. This “Bypass Logic” is what allows the coolant to circulate *only* within the engine block, allowing the engine to warm up rapidly and provide heat to the ‘Heater water drain switch’ (Comp 6).

3. Components: ‘Intermediate connecting pipe’ (1306023-36D) & ‘Single-pipe…’ (1306024-29D)
These (Comp 18 & 20) are the “Interface Logic.” These are rigid, pre-formed pipes that connect the FAW J6P Water Pump‘s “pressure side” to other components, such as the ‘FAW J6P Engine Oil Cooler’ module. They are used in tight spaces where a flexible rubber hose would kink, melt, or rub through.

Core 4: The “Sealing & Fastener” Logic (All Gaskets & Bolts)

This final group’s “logic” is to provide a 100% leak-proof, high-temperature, vibration-resistant seal for every connection in the FAW J6P Water Pump system.

1. The “Sealing” Logic (Gaskets & O-Rings)
This system uses three types of seals. The ‘Gasket’ (Comp 8) is a “Static Seal” for the flat, non-moving flange of the ‘Water pump seat’ (Comp 11). The ‘O-rings’ (Comp 10, 19, 25) are “Dynamic Seals.” Their “logic” is to seal the “slip-fit” ends of the intermediate pipes (Comp 9, 18, 20), allowing them to expand and contract with heat *without* leaking. Finally, the ‘Copper gaskets’ (Comp 12) are “Crush Washers” for the ‘Hollow bolts’ (Comp 13), creating a high-pressure, metal-on-metal seal for the heater circuit.

2. The “Fastener” Logic (Bolts & Nuts)
The entire FAW J6P Water Pump assembly is held to the block with a combination of ‘Hexagon flange stud bolts’ (Comp 27) and ‘Hexagon flange nuts’ (Comp 29, 30). This “Stud Logic” is superior for a high-vibration component. The studs are installed in the block, and the pump is placed over them, with nuts providing the clamp. This prevents wear on the engine block’s threads. The other ‘Hexagon flange bolts’ (Comp 15, 21) are used to secure the rigid pipes, with their “flange” providing a built-in, anti-vibration washer.

FAW J6P Water Pump & Filter Parts List

The following table provides the detailed breakdown of the 21 component types associated with the FAW J6P Water Pump and conditioning system (from the master “Thermostat & Water Pump” group) for the FAW Jiefang CA3250P66K2L1T1E 6×4 dump truck.

Core Specifications

The specifications for the FAW J6P Water Pump assembly are defined by its function as the “heart” of the engine’s cooling and conditioning system.