Bosch 0445020391 Common Rail High-Pressure Fuel Pump (0 445 020 391) | CPN2-Type Pump For WP12 Euro-5 / Shacman Applications — OE 1007203440

In heavy-duty common rail systems, the high-pressure pump is not "just a pump"-it's the pressure backbone that makes every injector event possible. When rail pressure becomes unstable, the symptoms can look like anything: slow starts, uneven idle, smoke under load, weak acceleration, or repeated rail-pressure codes that disappear and return. If you're searching 0445020391, you're usually trying to restore stable rail pressure delivery on a fleet vehicle where downtime is more expensive than the part itself.

The Bosch 0445020391 (Bosch No. 0 445 020 391) is widely sold online as a common rail high-pressure fuel injection pump and is often described as a CPN2-type / WPCPN2 pump in parts channels.
Many listings also pair it with the OE reference 1007203440, and a Russian parts retailer specifically labels it as a WP12 Euro-5 (ТНВД) application with the combined reference 0445020391/1007203440, marketed under Shaanxi parts categories.

Bosch pump number: 0445020391 / 0 445 020 391

OE cross reference often shown: 1007203440

Pump type keyword frequently used in listings: CPN2 / WPCPN2

Application keyword shown by retailer: WP12 Euro-5

These identifiers are what reduce wrong orders-especially when different sellers describe the same pump using different naming styles.

 

Because online catalogs vary by region, the safest fitment method is always match by part number. That said, the most consistent fitment signals shown in public listings include:

WP12 Euro-5 labeling (retailer listing 0445020391/1007203440)

Parts channel association with Shaanxi / Shacman categories for this pump number

Best practice for your customers: confirm 0 445 020 391 on the pump tag (or confirm 1007203440 on the OE list), then verify mounting pattern/gear drive and rail outlet layout before checkout.

 

 

Common rail engines don't need maximum pressure all the time-they need predictable pressure on demand. The pump's job is to supply pressurized fuel to the rail so the ECU can command injection events with precision. When the pump is worn or contaminated, performance becomes inconsistent in a way drivers describe as "random":

◆ Hard starting / long cranking (pressure builds slowly)
◆ Idle hunting (rail control keeps correcting)
◆ Smoke under load (fueling becomes less precise when pressure fluctuates)
◆ Power drop at high demand (rail pressure can't keep up)

Replacing the correct 0445020391 pump often resolves these "multi-symptom" complaints because it restores the system's ability to hold the ECU's rail target-especially under transient load (hill starts, heavy haul pull-away, overtakes).

 

 

Online B2B listings commonly present this pump as new, with use-case wording like "diesel truck" and the combined reference 0445020391 / 0 445 020 391 / 1007203440.
A retailer page also shows it as an in-stock SKU under the combined number 0445020391/1007203440, helping purchasers match quickly when they only have an OE reference.

To make your Google independent site more "decision-ready," include:

✅ Part numbers (Bosch + OE) near the top

✅ What's included (pump only vs. with accessories)

✅ Warranty & test policy (bench test / leakage / delivery checks if you offer them)

✅ Logistics note (this is a heavy-value item-package protection matters)

 

🛡️ Before installation
• Replace fuel filters and drain water separators
• Inspect fuel for contamination (metal/water)
• Flush/clean lines if pump failure was severe

🔧 After installation
• Prime and bleed air completely
• Verify rail pressure stability under load
• Recheck fittings after first heat cycle

A clean fuel system is the best "warranty" for any high-pressure pump.

 

 

To make your purchasing experience smooth and easy, we offer a variety of secure payment options:

We're here to make your order process worry-free - choose the payment method that works best for you!

 

 

Hot Tags: bosch 0445020391 common rail high-pressure fuel pump (0 445 020 391) | cpn2-type pump for wp12 euro-5 / shacman applications — oe 1007203440, China bosch 0445020391 common rail high-pressure fuel pump (0 445 020 391) | cpn2-type pump for wp12 euro-5 / shacman applications — oe 1007203440 manufacturers, suppliers, factory, Bosch for Mercedes, Euro 6 Tier 4 Final, Diesel Fuel Injection Pump 0445020050 ME225083, 0445020530, 1042300FE010