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Cummins QSB 4.5L High Pressure Fuel Rail 2013-2018: OEM 3977727

CUMMINS QSB 4.5L HIGH PRESSURE FUEL RAIL 2013-2018: OEM 3977727

Shipping ICON

ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY

WARRANTY ICON

WARRANTY
1M MILES OR 1 YEAR

$199.00

CORE CHARGE:

$150.00
iCORE DISCLAIMER: The CORE charge is a 30 day hold and will not be processed as long as the CORE is returned within 30 days. If you do not have a CORE or fail to return the CORE within 30 days, the CORE charge hold amount will be processed at that time.

AVAILABILITY IN STOCK
OEM NUMBER3977727
PART TYPEHigh Pressure Fuel Rail
BRANDTamerx Diesel Products
ENGINE MAKECummins
ENGINE TYPEQSB 4.5L
YEAR2013-2018
PART NUMBER3977727RM

PRODUCT DESCRIPTION

This is a Remanufactured Tamerx High Pressure Fuel Rail, Tamerx part number 3977727RM ( OEM Part Number 3977727 ). All parts are proudly remanufactured in the U.S.A. to the highest of OEM standards, and improvements are often applied to the original design in the remanufacturing process. This part is primarily made for a Cummins QSB 4.5L, production years 2013-2018, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here

OEM NUMBERS

Primary OEM3977727
Additional OEM107785-0160, 3963815, 3977727

ADDITIONAL DETAILS

CONDITIONRemanufactured
UPC / Barcode00840490539631
WEIGHT12.00 LBS

SHIPPING OPTIONS

Ship Weight : 12.00 LBS
UPS Ground, 2nd Day Air, Next Day Air

SHIPPING POLICY

Tamerx Diesel Products ships via UPS Ground. Next day air shipping can be arranged for a reasonable price of anywhere from $50.00 - $100.00 depending on the weight of the product and your location. We will do everything we can to make sure that you get the service you need. We understand how important it is to receive your order as quickly as possible.
In most cases Tamerx Diesel Products only needs one address, as long as your product is shipping to the same location as your billing information. In order to eliminate credit card fraud, your billing information must match the credit card you provide.

The terms, conditions, and details of our warranty vary from product to product. Specific warranty details can be found below.

Tamerx Diesel Products provides a replacement warranty on all of our parts. The duration and mileage limitations of the warranty vary by product and are specified on the product's detail page/item listing.

Please note that the warranty covers replacement of the part and the cost of shipping the replacement part to you only. It does not cover any shop, labor, towing, or any similar or related costs. This is not a "money back guarantee".

If you experience a problem with your part or it is not functioning properly, the correct warranty procedure is to call us at (510) 257-1777 (8:00 AM - 5:00 PM ET Monday through Friday). Be sure to have your order number and/or other relevant order information ready so we can easily locate your order and resolve your issue as quickly as possible. From that point, we will review with you any troubleshooting steps that may need to be taken and other areas or systems that can be checked to rule out external problems contributing to your part's issue. If a replacement is determined to be necessary, we will then arrange for your replacement part to ship out ASAP and issue any necessary return shipping labels and/or documents.

As is the case for the majority of the diesel products sold on Tamerx Diesel Products, your part's warranty is active as soon as you install it. In some other cases, warranty activation is contingent upon you sending us your core (i.e., your old part). Tamerx Diesel Products will provide you a return shipping label for parts that have a warranty with a core return condition. When we have received your core return, the part's warranty coverage begins. We reserve the right to void the product warranty if your core is not received within the allotted time, or if it isn't received at all. If the warranty for the diesel part you are purchasing has a core return requirement, it will be clearly noted on the product detail page/item listing.

What is a Core Charge?

A core charge (also called "core deposit") is similar to the deposit you might pay for a can or bottle of soda and is a standard requirement in the auto parts industry. For example, in many states, to promote recycling, you pay a deposit when you purchase a can of soda and receive your deposit back when you return the empty can. Many automotive parts have a core charge, or core price, that works in essentially the same way as a soda can deposit.

30 Day Core Charge Hold

You authorize Tamerx Diesel Products, to hold your credit card for the specified core charge amount and that you agree to return your core with 30 days of receiving the purchased part. When we have received your core return, the hold is released and the core charge payment is canceled.

The customer, or parts buyer, is responsible for any shipping costs associated with core returns unless otherwise specified in the product listing/detail page. Tamerx Diesel Products offers prepaid UPS shipping labels (SKU numbers UPS-CR1 and UPS-CR2) for use in returning your core that are available for purchase on our website during your shopping/order process.

The shipping label you will need to use for the core return is dependent upon what part you are purchasing. UPS-CR1 is good for cores weighing up to 20 pounds. UPS-CR2 is appropriate for shipping cores weighing 21 pounds or more. You must include enough information with the core return that clearly identifies it as a.) a Core Return, and b.) contains enough information we can use to clearly associate the core return with your order. Including a copy of the invoice or packing slip that came with the original shipment, clearly marked "Core Return", is ideal. Alternately, you can include a note marked as "Core Return" that includes your order number, full name and address, and phone number or other contact information. Failure to include this information with your returned core will most likely delay any due core credit being issued and/or delay any applicable warranty activation. Core returns need to be for the exact part purchased and cannot be damaged. Substituting another part in place of the part you have purchased is not acceptable.

All fluids must be drained.

If you have purchased a set or a parts package, you will need to return cores for all components of the set. For example, if you have purchaed a high pressure oil pump with an IPR valve, you will need to return both HPOP and IPR valve cores to receive proper credit. If you have purchased an EGR cooler/EGR valve package, your core return must consist of an EGR cooler core and an EGR valve core, or core credit will not be given.

Core Charges are often mandated by state legislature, and, as such, the actual core charge and taxes on the charge may vary depending on the state in which you buy your part. The Tamerx Diesel Products core charge presented to you online today with your item is representative of the most common core charge.


For 2013–2018 Cummins QSB 4.5L engine applications, the OEM 3977727 High Pressure Fuel Rail is manufactured to meet original equipment specifications for precise fit and dependable operation. This fuel rail serves as the central distribution point for high-pressure fuel, channeling it evenly to each injector within the common rail system. Built with durable materials and engineered tolerances, it is suited for the rigorous demands of modern diesel fuel systems. Proper fuel rail function supports balanced fuel delivery and consistent combustion across all cylinders. Tamerx Diesel Products LLC offers this Cummins QSB 4.5L high pressure fuel rail as a reliable solution for maintaining efficient fuel system operation.

FITMENT CHART

YEARMAKEENGINE(S)
2013Cummins QSB 4.5L
2014Cummins QSB 4.5L
2015Cummins QSB 4.5L
2016Cummins QSB 4.5L
2017Cummins QSB 4.5L
2018Cummins QSB 4.5L

PEOPLE ALSO ASKS | BLOG(S)

What Is the Main Role of the Cummins QSB 4.5L High Pressure Fuel Rail 2013–2018: OEM 3977727?

Consistent fuel pressure is essential in modern diesel engines, and the Cummins QSB 4.5L High Pressure Fuel Rail OEM 3977727 plays a central role in delivering that stability. Designed for 2013–2018 QSB 4.5L applications, this component serves as the main distribution channel for high-pressure fuel within the common rail system.

The primary role of the high pressure fuel rail is to store and supply pressurized fuel evenly to each injector. Fuel from the high-pressure pump enters the rail, where it is held at a controlled pressure before being delivered to the injectors on demand.

The Cummins QSB 4.5L High Pressure Fuel Rail is responsible for:

  • Maintaining stable high fuel pressure
  • Distributing fuel evenly to all injectors
  • Supporting precise fuel metering
  • Working with rail pressure sensors
  • Helping ensure consistent combustion

By keeping fuel pressure steady, the rail allows the injectors to deliver accurate amounts of fuel at the correct timing. Fluctuations in rail pressure can lead to uneven combustion, rough operation, and fault codes.

The OEM 3977727 fuel rail is engineered specifically for Cummins QSB 4.5L engines, ensuring proper fitment and compatibility with factory fuel system components. When functioning correctly, it supports balanced fuel delivery, smooth engine operation, and dependable performance in industrial and equipment applications.

The high pressure fuel rail delivers precisely pressurized fuel to your injectors. Because it operates under extreme pressure, maintaining a clean and stable fuel system is essential to extending its lifespan.

Contamination is one of the biggest threats to fuel rail durability.

To help prolong the lifespan of your high pressure fuel rail:

  • Replace the fuel filter at recommended intervals
  • Use clean, high-quality fuel from reputable sources
  • Avoid running the tank consistently near empty
  • Drain water separators regularly (for diesel systems)
  • Address fuel pressure fault codes promptly
  • Inspect for leaks or damaged fuel lines

Dirt, rust, and water in the fuel system can cause corrosion inside the rail. Over time, this can weaken internal surfaces and affect pressure consistency.

Fuel system components also work together. A failing high pressure pump or sticking regulator can create unstable pressure spikes that stress the rail.

Regular diagnostic checks and early attention to drivability issues can prevent small problems from escalating into larger fuel system damage.

By maintaining clean fuel flow and addressing issues quickly, you can significantly extend the service life of your high pressure fuel rail and protect other critical components in the system.

Yes, the 3977727 fuel rail is designed to match original fuel lines and injector connections.

The high pressure rail routes pressurized fuel from the supply pump to each injector for regulated delivery.

Yes, it is part of the Cummins high pressure common rail (HPCR) fuel system used on QSB 4.5L engines.

A properly functioning 3977727 fuel rail helps ensure even fuel distribution to all injectors for balanced engine combustion.

Cummins High Pressure Fuel Rails