3035346 Cummins PT Fuel Pump Shutoff Valve Assembly

 

The 3035346 is a critical shutoff valve assembly engineered specifically for the Cummins PT (Pressure-Time) fuel system, serving as the master control for fuel flow interruption in heavy-duty diesel engines. This genuine OEM-grade component replaces the factory fuel cutoff mechanism, ensuring positive engine shutdown by completely blocking fuel delivery to the PT injectors when the ignition is switched off. Designed for the demanding environments of mining, marine, construction, and agricultural operations, this valve assembly directly addresses the high-wear failure points inherent in mechanical diesel fuel systems, providing a direct-fit solution for maintaining the integrity of the Cummins PT fuel pump and preventing issues such as hard starting, fuel dilution of engine oil, and runaway diesel conditions.

 

---

 

The 3035346 shutoff valve is manufactured to exacting OEM tolerances for PT (G) and PT (H) fuel pump architectures. Operating via mechanical linkage or low-voltage electrical actuation, it physically closes the fuel passage within the gear pump outlet circuit. The valve body uses hardened alloy steel to withstand continuous fuel flow and pressure fluctuations typical of the Pressure-Time system, where pump outlet pressure ranges from 0.8 to 1.2 MPa (approx. 120–175 PSI). This assembly includes a precision-ground plunger and matched housing bore, maintaining tight clearances that prevent internal fuel bypass. When engaged, the valve eliminates fuel siphoning from overhead tanks-a common issue in high-mounted configurations that can cause hydraulic lock or crankcase oil dilution from unburnt fuel seeping past PT injectors.

 

---

 

This shutoff valve is universally compatible with Cummins heavy-duty diesel engines utilizing the PT fuel system, serving as a direct replacement for NH, NT, NTA, K19, K38, K50, and QSK series platforms. These engines are widely deployed in Caterpillar, Komatsu, Volvo, and TEREX heavy equipment. The 3035346 specifically integrates with the PT(G) pump-the most prevalent variant on post-1970s industrial engines-and also adapts to PT(H) high-flow pumps for larger displacement models. Whether installed in a D9 dozer, 777 haul truck, marine vessel, or stationary gen-set, this valve restores positive shut-off functionality essential for safety and maintenance, making it a critical replacement for shops servicing engines with fuel seepage past the throttle shaft or worn plunger assemblies.

 

---

 

Servicing the 3035346 shutoff valve requires strict cleanliness and torque adherence. The PT fuel system relies on low pressure and high volume, so any contamination can score the precision-mated plunger surfaces. Technicians must depressurize the fuel line and disconnect the battery before installation. The valve mounts to the top or side of the PT pump housing, adjacent to the PTG governor and throttle shaft. All included O-rings and copper sealing washers must be replaced-reusing old seals is a leading cause of air ingress and hard starting. Post-installation, adjust the valve linkage for full travel without binding, ensuring a positive stop in both "run" and "stop" positions. 

---

Inspection Point	Specification / Requirement
Plunger-to-bore clearance	0.025–0.050 mm (service limit)
Return spring free length	38.1 mm ± 0.5 mm
O-ring material	FKM (Viton®) for diesel compatibility
Mounting torque (valve nut)	30–35 Nm
Vent screw torque	7–9 Nm
Actuation voltage (if electric)	12V / 24V DC

 

---

 

While modern Common Rail diesel systems (e.g., Bosch CP4) are prone to catastrophic pump failure and metal contamination, the Cummins PT system operates differently, making the 3035346 shutoff valve a more serviceable but equally vital component. In PT systems, roughly 80% of fuel recirculates to cool and lubricate PT injectors, so the shutoff valve is crucial for hydraulic circuit integrity. A failing 3035346 often causes a "run-on" condition-engine continues running despite key-off-due to a broken return spring or internal leakage, a serious safety hazard in mining and marine applications. Replacing this worn valve prevents fuel drainage into cylinders, avoiding cylinder wall washing and oil dilution-a common cause of bearing failure in NH/NT series engines. For repair shops, stocking this valve offers a cost-effective alternative to full pump replacement or the extensive labor required for Common Rail contamination cleanup.

 

---

 

Q1： Is the 3035346 compatible with electronic PT pump upgrades or only mechanical versions?
A： This valve fits mechanical PT (G) and PT (H) fuel pumps only. It does not fit EFC (Electronic Fuel Control) versions unless confirmed against the pump's CPL number. Always verify your pump serial number.

Q2： What symptoms indicate shutoff valve failure rather than throttle shaft wear?
A： Engine fails to stop immediately when keyed off, or sputters after key-off, points to the shutoff valve. Black smoke at idle usually indicates throttle shaft wear, while fluctuating power suggests a bad pressure control valve (PCV).

Q3： Can a bad 3035346 cause fuel to enter the engine oil?
A： Yes. A leaking shutoff valve allows fuel to weep past PT injectors when parked-especially with high-mounted tanks-draining into cylinders and past piston rings, thinning the oil and risking bearing seizure.

Q4： What stock level is recommended for a shop rebuilding K19/K38 engines weekly?
A： For shops performing 3–5 major overhauls weekly, stocking 5–10 units per quarter is advisable, as spring fatigue and plunger wear make this a routine consumable in high-vibration applications.

Q5： Does this assembly include mounting gaskets and the return spring?
A： The 3035346 typically ships as a complete assembly with the pre-set return spring and high-pressure O-rings. In some aftermarket variants, O-rings are packed separately to prevent shipping damage.

 

 

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: 3035346 cummins pt fuel pump shutoff valve assembly, China 3035346 cummins pt fuel pump shutoff valve assembly manufacturers, suppliers, factory, 2036181 injector, 2419679 injector, 2897320, 4327147 injector, P2872321 nozzle, P4384781FSW