Frequently Asked Questions About International S1700-S1900 Fuel Tank Senders

Will these fuel tank senders work with my specific International S-Series truck model and year?

These fuel tank senders are designed to fit International S1700, S1800, and S1900 series trucks typically manufactured from the late 1980s through the early 2000s. However, compatibility can vary based on your specific tank configuration and sender type (mechanical vs. electrical). We recommend checking your existing sender's mounting pattern and ohm range (typically 0-90 or 33-240 ohms) before ordering. If you're unsure, contact us with your VIN or existing sender part number for verification.

How difficult is it to install a replacement fuel tank sender, and what tools will I need?

Installation typically takes 1-2 hours and requires basic hand tools including a hammer, drift punch, and socket set. The most challenging part is removing the old sender's lock ring, which may require a lock ring tool or large channel locks. You'll need to drain or significantly lower the fuel level in your tank before beginning. Many customers report that penetrating oil on the lock ring threads 24 hours before installation makes removal much easier. Always disconnect the battery before starting work.

What's the difference between mechanical and electrical fuel senders, and which one do I need?

Mechanical senders use a float arm connected directly to the gauge via a cable, while electrical senders use a float arm with a variable resistor that sends an electrical signal to your gauge. Most S-Series trucks from 1990 onward use electrical senders. You can identify your type by looking at the top of your current sender - mechanical units have a cable connection, while electrical units have wire terminals. Electrical senders are more common and generally more reliable in these applications.

Why is my new fuel sender giving inaccurate readings, and how can I fix it?

Inaccurate readings usually stem from three issues: incorrect ohm range for your gauge, improper float arm adjustment, or poor ground connection. First, verify your sender matches your gauge's ohm requirements. Second, ensure the float arm moves freely and isn't hitting the tank bottom or sides - you may need to bend the arm slightly. Finally, check that the sender has a solid ground connection to the tank, as corrosion at the mounting surface is a common culprit. Some customers add a dedicated ground wire from the sender to the chassis for better reliability.

How long do these replacement fuel senders typically last, and what causes them to fail?

Quality aftermarket fuel senders typically last 5-10 years depending on fuel quality and usage conditions. The most common failure points are the resistor board (in electrical units) and the float, which can develop pinholes and sink. Ethanol-blended fuels can accelerate wear on older-style senders. To maximize lifespan, choose senders with brass floats rather than plastic, and look for units with stainless steel components. Regular use of fuel additives to control moisture and prevent corrosion can also extend sender life significantly.