FAW J6P Air Compressor: Deconstructing 7 Critical Parts for Flawless Air Power

Welcome to this expert deconstruction of the FAW J6P Air Compressor (Main Assy P/N 3509010-382). This is the “compressed air generator” for the engine on the FAW Jiefang CA3250P66K2L1T1E 6×4 dump truck.

This is not an optional accessory; it is a safety-critical “Logic Assembly” of 7 component types. Its “logic” is to convert engine rotational power into high-pressure (120-150 PSI) compressed air, which is the lifeblood of the truck’s most critical systems: the air brakes, the clutch assist, the air suspension, and the horn.

The “Durability Logic” is the most important feature of this FAW J6P Air Compressor. Unlike a belt-driven compressor, this unit is “gear-driven” (see Comp 1, ‘Driven gear’). This “Gear-Drive Logic” means it is directly integrated with the engine’s internal timing train. This is a “life-of-the-engine” solution, as there is no belt to slip, break, or wear out—a critical design choice for a vehicle where a loss of air pressure means a total loss of braking. This FAW J6P Air Compressor is a piston-style pump, which requires its own lubrication and cooling.

This technical guide is an essential resource for engine technicians, chassis specialists, and parts managers. We will deconstruct the entire 7-component-type group. We will analyze the “Air Generation Logic” (the compressor assembly itself), the “Gear-Drive Logic” (the drive gear), the “Critical Lubrication Logic” (the oil inlet pipe and seals), and the “Sealing & Fastener Logic” (the hollow bolts and gaskets) that define this FAW J6P Air Compressor.

Core 1: The “Air Generation” Logic (Component 3)

This component is the main assembly, the “pump” itself. Its logic is to convert the engine’s rotational power into high-pressure compressed air.

1. Component: ‘Air compressor w/ pipe joint assy’ (3509010-382)
This (Comp 3) is the core FAW J6P Air Compressor assembly. This is a “piston pump” design, essentially a miniature, single-cylinder (or twin-cylinder) engine that works in reverse. It is driven by the ‘Driven gear’ (Comp 1), which turns an internal crankshaft and drives a piston up and down.

The “Valve Logic” is internal. On the “down-stroke,” the piston creates a vacuum, pulling in fresh, filtered air from the engine’s air intake via an “inlet reed valve.” On the “up-stroke,” it compresses this air to 120-150 PSI. This high-pressure air forces open an “outlet reed valve” and is pushed into the ‘pipe joint assy’ (the outlet), heading to the truck’s air tanks.

The “Thermal Logic” is critical. Compressing air creates an immense amount of heat. This FAW J6P Air Compressor is “liquid-cooled.” It features an internal “water jacket” (coolant passages) in its own cylinder head. Engine coolant is routed *through* the compressor body, where it absorbs this heat and carries it back to the main radiator. This is the only way the compressor can run continuously (a “100% duty cycle”) without seizing. The “pipe joint assy” specifies that this is the version of the FAW J6P Air Compressor that includes the critical outlet fittings.

Core 2: The “Engine-Drive” Logic (Component 1)

This component’s “logic” is to provide a reliable, “no-slip” power source for the FAW J6P Air Compressor.

1. Component: ‘Driven gear – air compressor’ (1006047-29D)
This (Comp 1) is the “Power Input Logic.” This is a heavy-duty, hardened steel gear. Its “logic” is to mesh *directly* with a gear on the engine’s “Timing Gear Train” (often the camshaft gear or an idler gear). This “Gear-Drive” design is the “Reliability Logic” for this safety-critical system. It *cannot* be driven by a belt, because a slipping or broken belt would mean an instant loss of brakes. This gear-on-gear connection ensures the FAW J6P Air Compressor is *always* spinning when the engine is running.

The “Helical Logic” of the gear teeth is also important. The teeth are “helical” (cut at an angle), not “spur” (straight). This design “logic” allows the teeth to engage gradually and quietly. This reduces the “whine” (NVH) of the gear train and, more importantly, reduces the “shock load” on the teeth as they mesh. This is essential for the long-term durability of the FAW J6P Air Compressor‘s drive system.

Core 3: The “Critical Lubrication” Logic (Component 7)

This group represents the “life-support” system for the FAW J6P Air Compressor. A piston pump cannot run dry.

1. Component: ‘Engine oil inlet pipe assy – air compressor’ (3509050-29D)
This (Comp 7) is the “Pressure Feed Logic.” Its “logic” is to be a high-pressure, rigid steel pipe that “taps” clean, pressurized oil directly from the engine’s main “oil gallery” (likely on the side of the engine block). This pipe’s “logic” is to provide a constant, pressurized stream of oil *into* the FAW J6P Air Compressor‘s internal crankcase.

This oil performs two critical functions:

• Lubrication: It lubricates the compressor’s own internal crankshaft, bearings, and piston cylinder wall.
• Cooling: It provides “splash cooling” to the underside of the compressor’s piston, drawing heat away and transferring it back to the engine’s main oil supply.

A failure in this “Lubrication Logic”—a clogged pipe, a loose “hollow bolt” (Comp 5), or a failed “copper gasket” (Comp 6)—will starve the FAW J6P Air Compressor of oil. This will cause it to overheat and seize in a matter of minutes, disabling the truck’s entire air system.

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

This final group’s “logic” is to provide a secure, vibration-proof, and *leak-proof* mounting for the FAW J6P Air Compressor and its fluid lines.

1. The “Structural Fastener” Logic (Component 4)
The ‘Hexagon flange bolt’ (Q1841035), of which there are three (3), is the “Mounting Logic.” These are the high-tensile bolts that hold the entire FAW J6P Air Compressor assembly (Comp 3) to its ‘support’ on the engine block. The “Flange Logic” (built-in washer) is critical for resisting the “rocking” vibration of the piston pump, ensuring the bolts do not “walk” loose.

2. The “Fluid Transfer” Logic (Components 5, 6)
This is the “Plumbing Hardware Logic” for the ‘Oil inlet pipe’ (Comp 7).

• ‘Hollow bolt’ (3509053-29D): The list calls for two (2) of these “banjo bolts.” Their “logic” is to allow fluid (oil) to flow *through* them, connecting the oil pipe to the engine block and to the FAW J6P Air Compressor inlet.
• ‘Copper gasket 10×16’ (Q/WC3403-1994): The list calls for four (4) of these. This “Crush Washer Logic” is critical. Two (2) gaskets are used *per* hollow bolt (one on each side of the banjo fitting). The soft copper “crushes” when tightened, creating a perfect, high-pressure, high-heat seal for the engine oil.

3. The “Main Seal” Logic (Component 2)
The ‘O-ring’ (Q734B1400265) is the “Mounting Gasket Logic.” This (Comp 2) is the large, high-temperature O-ring that seals the entire mounting flange of the FAW J6P Air Compressor to the engine block. Its “logic” is to seal two things: 1) It seals the “drive gear” (Comp 1) inside the timing case, preventing a massive oil leak. 2) It seals the “oil drain” path, allowing hot oil from the compressor’s crankcase to drain *back* into the engine’s main crankcase. A failure of this one O-ring will result in a major oil leak.

FAW J6P Air Compressor Parts List & Specifications

The following table provides the complete, detailed breakdown of all 7 component types identified in this FAW J6P Air Compressor assembly for the FAW Jiefang CA3250P66K2L1T1E 6×4 dump truck.

Core Specifications

The specifications for the FAW J6P Air Compressor are defined by its function as the primary air generator for the vehicle’s safety-critical brake system.