Peterbilt 567/579 Fuel Tank Senders

Frequently Asked Questions About Peterbilt 567/579 Fuel Tank Senders

What does a fuel tank sender do?

The fuel tank sender is the component inside your fuel tank that monitors fuel level and sends that data to your dash gauge. It typically uses a float arm connected to a variable resistor, so as fuel level changes, the resistance changes and your gauge reading updates accordingly. If your fuel gauge is reading inaccurately, stuck, or not moving at all, a failing sender is a common cause.

How do I know if I need a new sender versus another fuel system part?

Common signs of a failing sender include a fuel gauge that reads empty when the tank is full, a needle that fluctuates erratically, or a gauge that stays at one reading regardless of fuel level. Before replacing the sender, it is a good idea to check wiring connections and the dash gauge itself, since those can cause similar symptoms. If the wiring and gauge test out fine, the sender is likely the culprit.

Will this sender fit my specific Peterbilt 567 or 579 fuel tank?

Fuel tank senders can vary by tank size, mounting configuration, and model year, so it is important to match the sender to your truck's specific tank setup rather than assuming universal fit. Check your existing sender's part number or your tank specifications before ordering, and reach out to our team if you are unsure - we can help confirm the correct match for your application.

What is involved in replacing a fuel tank sender?

Replacement generally involves draining or reducing fuel level in the tank, removing the tank strap or accessing the sender mounting plate, disconnecting the wiring, and unbolting the old sender before installing the new one with a fresh gasket. Because this job involves working around fuel, proper precautions and ventilation are necessary. If you are not comfortable working around fuel systems, having a qualified technician handle the installation is recommended.

Do these senders come with a gasket, and should I reuse the old one?

Many replacement senders include a new mounting gasket, but it is worth confirming what is included with your specific part before starting the job. Reusing an old, worn gasket can lead to fuel leaks or air getting into the sending unit, so we recommend always installing a new gasket when you replace the sender, even if you have to order one separately.