REV Fire Group Cummins ISL DEF Head Unit
REV FIRE GROUP CUMMINS ISL DEF HEAD UNIT
ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY
WARRANTY
1M MILES OR 1 YEAR
PRODUCT DESCRIPTION
This is a Remanufactured, Tamerx DEF Head Unit, Tamerx part number 4310-11-14 ( OEM Part Number 726853 ). This part is primarily made for a Cummins ISL, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here
Additional Notes: DEF Header, 40 MICRON, 11"
OEM NUMBERS
| Primary OEM | 726853 |
| Additional OEM | 077905V012-01, 077905V015-01, 100417V005, 1009209-001, 1047196-002, 1096417-003, 1113741-002, 717558, 721453, 726853 |
ADDITIONAL DETAILS
| CONDITION | Remanufactured |
| UPC / Barcode | 00840490540125 |
| WEIGHT | 8.00 LBS |
SHIPPING OPTIONS
Ship Weight : 8.00 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.
Reliable DEF system management comes from the REV Fire Group Cummins ISL DEF Head Unit: OEM 726853, a direct-fit replacement for compatible fire service vehicles and equipment. Built to OEM standards, this unit monitors fluid level, temperature, and quality to support emissions compliance and steady aftertreatment performance. Its durable construction provides long-lasting reliability under demanding conditions, protecting both the exhaust system and engine efficiency. By choosing an OEM DEF head unit, you reduce compatibility risks and ensure consistent operation over time. This component is a dependable solution for keeping REV Fire Group Cummins-powered apparatus operating effectively and without interruption.
PEOPLE ALSO ASKS | BLOG(S)
The DEF Head Unit, part number 726853, is a vital part of the emissions control system on REV Fire Group vehicles equipped with Cummins ISL engines. Mounted directly on top of the DEF (Diesel Exhaust Fluid) tank, this unit combines multiple sensor and fluid management features to ensure the proper function of the Selective Catalytic Reduction (SCR) system.
So, what exactly makes up this intelligent module?
Key Components Inside the 726853 DEF Head Unit
- DEF Level Sensor
- This sensor monitors the amount of DEF in the tank and communicates with the engine control module to warn when levels are low.
- Temperature Sensor
- It keeps tabs on the DEF fluid temperature, ensuring it doesn't freeze or overheat—both of which can affect DEF dosing and engine compliance.
- Internal Filter
- A fine mesh screen, typically around 40 microns, protects the system from DEF crystallization, dirt, or other contaminants.
- Suction and Return Ports
- These ports manage the movement of DEF to and from the dosing module, keeping the fluid flowing correctly through the emissions system.
- Electrical Connector
- Links the unit’s sensors to the vehicle’s control system, enabling real-time communication and fault detection.
- Mounting Flange and Housing
- A durable structure that seals the unit to the tank and houses all internal components securely.
Each element of the 726853 DEF head unit plays a crucial role in emissions performance, engine health, and system efficiency. If even one component fails, it can lead to warnings, engine derate, or non-compliance with emissions standards. That’s why regular inspection and quality replacement are essential.
The DEF (Diesel Exhaust Fluid) head unit is a vital part of the emissions control system in modern diesel vehicles. It monitors the level, temperature, and quality of DEF in the tank. When this unit starts to fail, the entire aftertreatment system can be affected.
Common Symptoms of a Faulty DEF Head Unit
If your DEF head unit is going bad, you may notice several of the following issues:
- Incorrect DEF level readings
- The gauge may show full or empty inaccurately
- Frequent warning messages
- Alerts like “Service DEF System” or “Incorrect DEF Quality”
- Unexpected derates
- The engine may limit speed or torque without a clear cause
- Check engine or emission lights
- Fault codes related to DEF sensors or tank level
- Increased DEF usage
- More fluid consumption than usual without any changes in driving
- Intermittent sensor signals
- DEF temperature or quality readings may fluctuate
If you observe any of these signs, it’s important to run a diagnostic scan. A technician can confirm whether the issue is with the head unit, wiring, or another part of the system.
It can lead to inaccurate DEF readings, fault codes, and potential downtime.
Yes, it is built to withstand extreme temperatures, vibration, and emergency service conditions.
No, it must be replaced if it fails.
It provides precise DEF monitoring to prevent emission-related engine derates.
Cummins DEF Head Units
