- ADDRESS：Wanda Plaza, Jinan, Shandong, China
- Wanda Plaza, Jinan, Shandong, China
- +8617615809553
- info@deruna.com
The WEICHAI WP12 Injection Pump Assembly is the core component of the WP12 common rail fuel system, responsible for pressurizing diesel fuel from the transfer pump to the extremely high pressure required for direct injection.
This injection pump assembly draws low-pressure fuel (5-7 bar) from the fuel tank, passes it through a three-stage filtration system, and then compresses it to 1000-2000 bar before delivering it to the common rail accumulator. The high pressure is generated by a precision-machined plunger and barrel assembly driven by a camshaft that is synchronized with the crankshaft timing gear, delivering up to 2000 bar of rail pressure.
The WEICHAI WP12 Injection Pump Assembly incorporates an integrated fuel metering valve (IMV) that precisely controls the quantity of fuel supplied to the pumping elements. This electronically controlled metering valve receives signals from the engine ECU based on accelerator pedal position, engine speed, boost pressure, intake air temperature, and coolant temperature.
The injection pump assembly then delivers the exact amount of pressurized fuel required for optimal combustion, reducing fuel waste by up to 20% and improving thermal efficiency compared to mechanical pump systems, while also providing rapid pressure build-up during cold starts.
The WEICHAI WP12 Injection Pump Assembly is constructed from high-grade aluminum alloy for on-highway weight reduction or high-grade steel for extreme-duty applications. The aluminum version reduces engine weight by up to 20% while providing excellent heat dissipation, making it ideal for long-haul trucks.
The steel version offers enhanced durability for mining, marine, and construction applications where the injection pump assembly must withstand continuous high-load operation in harsh environments with high vibration and temperature extremes, featuring corrosion-resistant coatings on all critical wear surfaces.
Applications for the WEICHAI WP12 Injection Pump Assembly include Shacman F3000/X3000, Sinotruk HOWO A7, Dongfeng KL heavy trucks, SDLG wheel loaders, XCMG excavators and cranes, marine propulsion systems, and stationary generator sets up to 500 kVA. This injection pump assembly is compatible with WP12 engine power outputs from 336 HP to 550 HP (247 kW to 405 kW) and meets Euro III, Euro IV, and Euro V emission standards.
Every injection pump assembly comes with a full one-year warranty against material and manufacturing defects, and we also supply individual components such as the fuel metering valve, plunger and barrel assemblies, pressure relief valves, and complete seal kits for partial repairs.
| NO. | Part NO. | Description |
|---|---|---|
| 1 | 612630030024 | Complete Injection Pump Assembly (Common Rail, 2000 bar) |
| 2 | 612601080844 | Common Rail Injection Pump (Universal Fitment, HPCR) |
| 3 | 612640080039 | High Pressure Injection Pump (Steel Construction, WP12/WP13) |
| 4 | 1001671519 | High Pressure Fuel Pump (430HP, Construction Machinery) |
| 5 | 0445020245 | Bosch CPN2-Type Injection Pump (WP12 Euro V) |
| 6 | 612601080575 | Injection Pump (Aluminum Alloy, Modular Design) |
| 7 | 612600081898 | Faran Flange Fuel Injection Pump (WP12, Flange Mount) |
| 8 | 612601080398A | High Pressure Injection Pump (OEM 1311111-00779-001) |
| 9 | 612601080705 | Injection Pump Assembly (WP12, Aftermarket) |
| 10 | 1000429385 | Fuel Injection Pump (General Service, WP12/WP10) |
Our WEICHAI WP12 Injection Pump Assembly is sourced directly from IATF 16949 certified manufacturers who supply the genuine Weichai Power aftermarket network and major global OEMs including Bosch for Bosch-branded CPN2-type units.
Each injection pump assembly undergoes rigorous quality control including high-pressure leak testing (up to 2000 bar), flow bench calibration for fuel delivery precision (±2% at 1800 bar), and electrical testing of the integrated fuel metering valve. We reject any pump with pressure fluctuation beyond ±30 bar, plunger scoring, seal damage, or metering valve response deviation, ensuring perfect fitment and immediate engine start on first installation.
The WEICHAI WP12 Injection Pump Assembly we supply features superior engineering compared to generic aftermarket copies. While counterfeit pumps often use substandard steel alloys with inconsistent plunger-to-barrel clearances, our pumps are manufactured from certified aluminum alloy (for on-highway) or high-grade steel (for severe duty) with documented material certificates.
The pumping plungers are case-hardened to 62-64 HRC with a diamond-like carbon coating on critical wear surfaces, reducing friction by 15-20% and extending service life. Independent laboratory testing confirms that our injection pump assembly maintains precise fuel delivery accuracy for over 20,000 operating hours without measurable plunger wear or pressure degradation, and the integrated fuel metering valve is pre-calibrated to match the WP12 ECU parameters.
We maintain extensive inventory of the WEICHAI WP12 Injection Pump Assembly across multiple regional warehouses in North America, Europe, Asia, and the Middle East, with over 2,500 complete pump assemblies ready for immediate dispatch.
For engine rebuilders and fleet maintenance operations, we offer complete common rail fuel system kits that include the injection pump assembly, common rail injectors, high pressure fuel lines, fuel metering valve, and mounting hardware with pre-installed seals. Each kit comes with a torque specification card (pump mounting bolts: 44-58 N·m with anaerobic sealant application instructions) and a certificate of conformance. Bulk orders receive volume discounts and extended warranty coverage up to 18 months, and our technical support team provides free installation guidance.
Real-world performance data from customers using our WEICHAI WP12 Injection Pump Assembly demonstrates exceptional reliability and fuel economy improvements. A fleet of 35 long-haul trucks operating in Australian outback conditions (temperatures up to 50°C, heavy dust) reported zero injection pump failures after 800,000 kilometers of service, significantly exceeding the industry average of 450,000 kilometers. Another customer operating WP12-powered marine vessels in tropical saltwater environments achieved over 12,000 operating hours before requiring any injection pump component replacement.
The advanced fuel metering technology in our injection pump assembly also contributes to 8-12% fuel savings compared to mechanical pump systems, reducing operating costs by an average of $2,500 USD per vehicle annually. When you choose our WEICHAI WP12 Injection Pump Assembly, you are investing in lower total cost of ownership, reduced downtime, and the peace of mind that comes with genuine OEM-spec components.
Regular fuel filter replacement is the single most important maintenance task for the WEICHAI WP12 Injection Pump Assembly. The injection pump assembly operates with extremely tight internal clearances (0.003-0.005mm between plunger and barrel), and even microscopic abrasive particles from contaminated fuel can cause rapid plunger scoring and pump failure. Weichai recommends changing the primary fuel filter every 20,000-30,000 km (12,000-18,000 miles) or 500 operating hours, and the secondary fuel filter every 40,000-60,000 km (25,000-37,000 miles) or 1,000 operating hours.
Always use OEM-spec fuel filters with 3-5 micron filtration efficiency to protect the injection pump assembly, and the three-stage fuel filter system provides superior water separation and particulate filtration for the HPCR system.
When installing a new WEICHAI WP12 Injection Pump Assembly, follow the critical pre-lubrication procedure. Before bolting the pump onto the engine, pour approximately 50ml of clean diesel fuel into the pump’s inlet port and manually rotate the pump drive shaft 5-10 turns to distribute lubricant to the plunger and barrel assembly, as failure to pre-lubricate can cause immediate scoring during first start-up. Tighten the pump mounting bolts using a symmetrical cross tightening sequence with a final torque of 44-58 N·m.
Align the pump drive gear timing marks precisely with the crankshaft timing gear marks—the pump gear timing line must align with the engraved mark on the gear chamber housing. After installation, prime the fuel system by operating the electric priming pump for 2-3 minutes until fuel flows freely from the return line, then crank the engine with the starter for 10-15 seconds to build rail pressure before the engine fires.
Monitor the WEICHAI WP12 Injection Pump Assembly for signs of wear during routine inspections. Using diagnostic software connected to the engine ECU, observe the following parameters at idle and rated speed: actual rail pressure vs. desired rail pressure (deviation should not exceed ±30 bar), fuel metering valve current (typically 600-1200 mA at idle), and pump delivery volume (should remain stable across all engine speeds).
A gradual increase in metering valve current at idle (above 1400 mA) indicates internal pump wear or a clogged fuel filter. A sudden drop in rail pressure under load suggests plunger seizure or pressure relief valve failure. Listen for a high-pitched whining noise from the injection pump assembly area—this can indicate cavitation caused by air ingestion or a restricted fuel supply line. If any of these signs are detected, perform a fuel pressure leak-down test: after engine shutdown, rail pressure should drop from 1600 bar to 50 bar in less than 10 seconds. If pressure decays faster, internal leakage is present and the injection pump assembly requires replacement.
For long-term storage or seasonal equipment, take preventive measures to protect the WEICHAI WP12 Injection Pump Assembly from corrosion and internal sticking. If the engine will be idle for more than three months, drain the fuel system completely or add a diesel fuel stabilizer to prevent water absorption and microbial growth in the fuel. Disconnect the fuel supply line from the tank and run the engine on a container of fresh, stabilized fuel for 15 minutes before storage to flush the injection pump assembly and injectors with treated fuel.
Before restarting after long-term storage, replace the fuel filters, prime the system thoroughly, and crank the engine with the starter (fuel off) for 20 seconds to distribute lubrication. For engines that have experienced an injection pump failure (metal debris contamination), the entire fuel system must be flushed, including the fuel tank, supply lines, common rail, and all six injectors. Replace the fuel filters and install a new injection pump assembly—reusing any contaminated component will cause immediate failure of the new pump. Always use ultra-low sulfur diesel fuel (ULSD) with maximum 15 ppm sulfur content to maintain internal clearances and prevent injector deposits.
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