Frequently Asked Questions About Freightliner FLT Cabover Fuel Tank Senders

Will these fuel tank senders fit my specific Freightliner FLT model year?

Our fuel tank senders are designed to fit Freightliner FLT cabover models from 1984 through 1991. However, compatibility can vary based on your specific tank configuration. The most common fitments are for 50-gallon and 100-gallon tanks with either single or dual tank setups. Before ordering, verify your tank capacity and whether you have a step tank or standard mount configuration. If you're unsure, check the sender arm length - standard units typically use 12-inch or 24-inch arms depending on tank depth.

What's the difference between OEM and aftermarket senders, and which should I choose?

OEM senders use the original 0-90 ohm resistance range and typically feature brass or stainless steel float arms with nitrophyl floats. Aftermarket options often use 240-33 ohm resistance (more common in modern gauges) and may have plastic components. If you're keeping your original gauge cluster, stick with OEM-spec senders. Aftermarket units work well if you've upgraded to digital gauges or universal dash panels. Quality aftermarket brands like VDO and Stewart Warner offer comparable accuracy to OEM at a lower price point.

How difficult is the installation, and what tools do I need?

Installation typically takes 1-2 hours per tank. You'll need a 1-7/8 inch socket or sender wrench, thread sealant, and basic hand tools. The main challenge is accessing the sender on top of the tank - you may need to drop the tank partially or remove the bed floor panel. Always drain the tank below the sender level before removal. Common issues include corroded lock rings (use penetrating oil) and ensuring proper float arm clearance. The sender must be clocked correctly so the float doesn't hit the tank walls.

Why is my new sender giving inaccurate readings?

The most common cause is resistance mismatch between your sender and gauge. Verify your gauge requires the same ohm range as your sender. Ground connection problems are the second leading cause - ensure you have a dedicated ground wire from the sender to the frame, not just relying on tank ground. Also check that the float arm moves freely through its full range without binding. Some FLT models require calibration adjustment at the gauge. If readings are reversed (full shows empty), the signal wire may be connected to the wrong terminal.

How long do these senders typically last, and what causes failure?

Quality senders typically last 8-12 years in normal service. Sulfur content in diesel fuel is the primary cause of failure, corroding the resistance strip inside the sender. Symptoms of failing senders include erratic gauge readings, stuck readings, or dead zones in the sweep. Water contamination accelerates failure. To maximize lifespan, use fuel additives that reduce sulfur corrosion, keep tanks above quarter full to minimize condensation, and ensure proper tank venting. Consider upgrading to stainless steel units if you operate in high-humidity environments.