Adjusting your electric trailer brakes properly is crucial for safe towing. This involves setting the brake shoes inside the drum to provide optimal stopping power without dragging, ensuring balanced braking performance across all trailer axles.
Understanding Electric Trailer Brakes
Electric trailer brakes offer a significant advantage in towing safety, allowing you to smoothly and effectively control your trailer’s braking independently of your tow vehicle. Unlike surge brakes that rely on inertia, electric brakes use an electrical signal from the tow vehicle to activate electromagnets within the brake drums. These electromagnets pull on the brake shoes, pressing them against the drum’s inner surface and creating friction to slow the trailer. Properly adjusted electric brakes are essential for preventing swaying, reducing stopping distances, and extending the lifespan of both your tow vehicle and trailer brakes. Without proper adjustment, you risk uneven braking, premature wear, and potentially dangerous towing conditions.
The Adjustment Process: Step-by-Step
Adjusting electric trailer brakes, while seemingly complex, is a manageable task with the right tools and understanding. Before starting, gather the necessary equipment: a jack and jack stands, a brake adjustment tool (also known as a “spoon”), a screwdriver, a wheel chock, and a torque wrench. Safety is paramount, so always wear safety glasses and gloves.
Step 1: Prepare the Trailer
- Chock the wheels: Place wheel chocks behind the wheels on the opposite side of the trailer from the wheel you’ll be adjusting. This prevents the trailer from rolling.
- Jack up the trailer: Use a jack to lift the trailer wheel off the ground. Securely place a jack stand under the axle or frame near the wheel for support. Never work under a trailer supported only by a jack.
- Release the parking brake: Ensure the trailer’s parking brake is disengaged.
Step 2: Locate the Adjustment Slot
On the backing plate of the brake assembly (the metal plate behind the wheel), you’ll find an oval-shaped adjustment slot. This slot is usually covered by a rubber or plastic plug. Remove this plug to access the star wheel adjuster.
Step 3: Adjust the Brakes
- Insert the brake adjustment tool: Insert the spoon-shaped end of the brake adjustment tool into the adjustment slot.
- Tighten the brakes: Use the tool to rotate the star wheel adjuster in a clockwise direction (usually). You should hear a clicking sound as the adjuster teeth engage. Continue tightening the adjuster until the brake shoes press firmly against the drum, making it nearly impossible to turn the wheel by hand.
- Back off the adjuster: Once the wheel is tightly bound, use the tool to back off the adjuster approximately 8 to 10 clicks. This allows the wheel to turn freely without dragging. The aim is to achieve a slight drag, indicating that the brake shoes are close to the drum.
Step 4: Test the Wheel
Rotate the wheel by hand. It should spin freely with a very slight drag. If the wheel is completely free-spinning, tighten the adjuster another click or two. If the wheel is still tightly bound, back off the adjuster another click or two.
Step 5: Repeat for All Wheels
Repeat steps 1 through 4 for each wheel on the trailer. Consistency in brake adjustment across all wheels is crucial for balanced braking.
Step 6: Final Checks
- Replace the adjustment slot plugs: Once all brakes are adjusted, replace the rubber or plastic plugs in the adjustment slots to prevent dirt and debris from entering the brake assembly.
- Lower the trailer: Carefully lower the trailer to the ground and remove the jack stands.
- Torque the lug nuts: Use a torque wrench to tighten the lug nuts to the manufacturer’s specified torque.
- Test the brakes: Conduct a test run at low speeds to ensure the brakes are functioning correctly and evenly. Listen for any unusual noises.
Troubleshooting Common Issues
Even with careful adjustments, issues can arise. Common problems include brake dragging, uneven braking, and noisy brakes. These can often be attributed to worn brake shoes, contaminated brake surfaces, or improperly adjusted brakes. Regular inspection and maintenance are key to preventing these issues.
Frequently Asked Questions (FAQs)
FAQ 1: How often should I adjust my electric trailer brakes?
Adjust your electric trailer brakes every 3,000 miles or at least once a year, whichever comes first. More frequent adjustments may be necessary if you tow frequently or in challenging conditions (e.g., mountainous terrain, heavy loads).
FAQ 2: What tools are absolutely necessary for adjusting electric trailer brakes?
You’ll need a jack and jack stands, a brake adjustment tool (spoon), a screwdriver, a wheel chock, a torque wrench, safety glasses, and gloves.
FAQ 3: Can I adjust electric trailer brakes without a special brake adjustment tool?
While technically possible with a screwdriver, it’s strongly discouraged. The brake adjustment tool is designed to safely and effectively engage the star wheel adjuster without damaging it. Using a screwdriver can strip the teeth on the adjuster.
FAQ 4: How do I know if my electric trailer brakes are properly adjusted?
Properly adjusted brakes will provide a slight drag when the wheel is spun by hand. During a test run, the trailer should brake smoothly and evenly without pulling to one side or feeling jerky.
FAQ 5: What causes electric trailer brakes to drag?
Brake dragging can be caused by overly tight adjustment, worn brake shoes, rusty brake drums, or a malfunctioning brake controller.
FAQ 6: What do I do if the star wheel adjuster is stuck or won’t turn?
Penetrating oil can help loosen a stuck adjuster. Apply it to the adjuster through the slot and let it soak for a while. If it still won’t budge, you may need to disassemble the brake assembly for cleaning and lubrication. If the adjuster is severely corroded, it may need to be replaced.
FAQ 7: How do I troubleshoot uneven braking?
Uneven braking is often caused by unevenly adjusted brakes. Make sure each brake is adjusted properly. Other causes include contaminated brake shoes (oil or grease), worn brake shoes on one side, or a faulty brake controller.
FAQ 8: Can I use automatic adjusting electric trailer brakes?
While some manufacturers offer self-adjusting electric brakes, it’s still important to periodically inspect them. Over time, the self-adjusting mechanism can fail, requiring manual adjustment.
FAQ 9: What does the brake controller setting do?
The brake controller setting adjusts the amount of power sent to the trailer brakes. A higher setting applies more braking force, while a lower setting applies less. The correct setting depends on the weight of the trailer and the towing conditions.
FAQ 10: What if my electric brakes are making a lot of noise?
Noisy brakes can indicate worn brake shoes, rusty brake drums, or foreign objects (like stones) lodged in the brake assembly. Disassemble the brake assembly to inspect for wear and tear and remove any debris.
FAQ 11: Can I convert my trailer to electric over hydraulic brakes?
Yes, it’s possible to convert to electric over hydraulic (EOH) brakes, which provide more powerful and responsive braking, especially for heavier trailers. However, this is a more complex and expensive conversion than simply adjusting electric drum brakes.
FAQ 12: Where can I find the correct torque specifications for my trailer wheel lug nuts?
The correct torque specifications are usually found in your trailer’s owner’s manual or on a sticker on the trailer’s frame. If you can’t find this information, consult with a reputable trailer repair shop. Always use a torque wrench to ensure the lug nuts are tightened to the correct specification. Over-tightening or under-tightening lug nuts can be dangerous.