C3957290 XCMG GR2605 motor grader check valve

C3957290 is an original equipment manufacturer (OEM) fuel injector return check valve for Cummins engines. As a key one-way control component in the fuel system, it allows fuel to flow only from the fuel injector return line to the main return line, preventing backflow and air intrusion. It ensures stable pressure in the return line, avoids rail pressure fluctuation caused by backflow, poor lubrication of fuel injectors, and fuel path air intrusion, making it a core accessory to maintain the normal operation of fuel injectors and stable pressure of the fuel system.

Part Number: C3957290
Type: Fuel injector return check valve (one-way non-return type)
Compatible System: Cummins electronic controlled high-pressure common rail fuel system
Core Specifications: M12×1.5 thread interface, valve body aperture about 3.5mm, total length about 31mm
Sealing Configuration: Equipped with M12 and M14 sealing gaskets to ensure fuel path sealing
Compatible Materials: Suitable for steel return lines, matches the standard return interface of Cummins engine cylinder head
Weight: About 0.05kg

Applicable Engines：

Equipment：

Location：

At the interface of the fuel injector return line on the rear side of the engine cylinder head, connecting the fuel injector return branch pipe to the engine main return line for easy disassembly, assembly and maintenance.

Fuel Leakage at Return Line

Causes: Worn valve seat, failed spring, aged or damaged sealing gasket.
Symptoms: Fuel seepage or dripping at the return line interface; unstable engine idle, power loss, increased fuel consumption; abnormal return oil volume when accelerating.
Solution: Replace C3957290 check valve and supporting sealing gaskets; tighten to standard torque during installation to ensure close fit of the sealing surface.

Air Intrusion in Fuel Path

Causes: Poor sealing of check valve, misaligned installation, loose line interface.
Symptoms: Hard engine starting, idle jitter, air bubbles in fuel path, accelerated wear of fuel injectors due to poor lubrication.
Solution: Inspect the sealing performance of the check valve and replace damaged components; reinstall to ensure aligned interface; bleed air from the fuel path before starting the engine.