Installing electric trailer brakes is a crucial step for safe and responsible towing, fundamentally enhancing braking performance and control, especially when hauling heavier loads. While it might seem daunting, with the right tools, understanding, and a systematic approach, you can successfully install electric trailer brakes, significantly improving your towing safety and peace of mind.
Understanding Electric Trailer Brakes
Electric trailer brakes utilize an electromagnet activated by the towing vehicle’s brake pedal to apply pressure to the brake shoes inside the trailer’s brake drums. This synchronized braking action reduces the strain on your tow vehicle’s brakes, prevents trailer sway, and shortens stopping distances. Before beginning the installation process, it’s essential to ensure your trailer is equipped with the necessary brake flanges to accommodate the electric brake assemblies.
Preparation and Tools
Before you dive into the installation, gather all the necessary tools and components. This upfront preparation will save you time and frustration later. Here’s a comprehensive list:
- Electric Brake Assemblies: Choose the correct size and capacity for your trailer’s axle rating.
- Brake Controller: A proportional controller is highly recommended for smoother, more responsive braking.
- Wiring Harness: Use a 7-way connector harness designed for electric brakes.
- Brake Wiring: 12-gauge wire is standard, but consult your brake controller’s manual.
- Wiring Connectors: Crimp-on connectors or solder and heat shrink are ideal.
- Wire Strippers/Crimpers: Essential for secure wiring connections.
- Multimeter: For testing voltage and continuity.
- Jack and Jack Stands: For safely lifting and supporting the trailer.
- Wheel Chocks: To prevent the trailer from rolling.
- Socket Set and Wrenches: Various sizes for removing and installing components.
- Torque Wrench: To tighten nuts and bolts to the manufacturer’s specifications.
- Pliers: For various tasks.
- Screwdrivers: Phillips and flathead.
- Drill and Drill Bits: For mounting the brake controller and running wires.
- Zip Ties: To secure wiring along the trailer frame.
- Electrical Tape: For insulating connections.
- Brake Cleaner: To clean brake surfaces.
- Grease: For lubricating brake components.
- Gloves and Safety Glasses: For personal protection.
Step-by-Step Installation Guide
This section provides a detailed, step-by-step guide to installing electric trailer brakes. Always refer to the specific instructions included with your brake assemblies and brake controller for model-specific information.
Step 1: Safety First!
- Park the trailer on a level surface.
- Apply the wheel chocks securely to the wheels that won’t be worked on.
- Disconnect the trailer from the tow vehicle.
- Disconnect the trailer’s battery (if equipped).
- Use the jack and jack stands to safely lift and support the trailer axle.
Step 2: Removing Existing Hubs and Drums (If Applicable)
- Remove the wheel from the axle.
- Carefully remove the dust cap from the hub.
- Remove the cotter pin and nut securing the spindle.
- Pull off the hub and drum assembly. Be prepared for some resistance, especially if the bearings are old.
Step 3: Mounting the Brake Flange (If Necessary)
- If your trailer doesn’t already have brake flanges, you will need to install them. These are typically welded onto the axle. This step requires welding expertise and should be performed by a qualified professional. Ensure the flange is properly aligned to accept the brake assembly.
Step 4: Installing the Electric Brake Assembly
- Slide the electric brake assembly onto the spindle, aligning it with the mounting bolts on the brake flange.
- Secure the brake assembly using the provided bolts. Torque the bolts to the manufacturer’s specifications.
- Adjust the brake shoes so that they are centered within the drum.
Step 5: Packing and Installing New Bearings
- Thoroughly clean and inspect the bearings and races. Replace them if they show any signs of wear or damage.
- Pack the bearings with high-quality bearing grease.
- Install the inner bearing and grease seal.
- Carefully slide the hub and drum assembly back onto the spindle.
- Install the outer bearing, washer, and nut.
- Tighten the nut to the manufacturer’s specifications. It’s usually a snug fit, then backed off slightly to allow for proper bearing movement.
- Install a new cotter pin to secure the nut.
- Reinstall the dust cap.
Step 6: Wiring the Brake Assemblies
- Run the wires from the brake assembly along the axle, securing them with zip ties to prevent them from dangling.
- Connect the wires from each brake assembly to the main wiring harness. Use crimp connectors or solder and heat shrink for secure, weatherproof connections.
- Ensure the wiring is properly insulated with electrical tape.
- Ground one of the brake wires to the trailer frame near the brake assembly.
Step 7: Running the Wiring Harness
- Run the main wiring harness along the trailer frame, securing it with zip ties.
- Connect the 7-way connector to the trailer’s tongue.
- Ensure the wiring harness is protected from abrasion and damage.
Step 8: Installing the Brake Controller
- Mount the brake controller in a convenient and accessible location inside the tow vehicle, following the manufacturer’s instructions.
- Connect the brake controller wiring to the tow vehicle’s electrical system, following the manufacturer’s wiring diagram. This typically involves connecting to the battery, brake light switch, and ground.
- Run the blue wire from the brake controller to the 7-way connector on the tow vehicle. This is the brake output wire that carries the signal to the trailer brakes.
Step 9: Testing the Brake System
- Connect the trailer to the tow vehicle.
- Use a multimeter to verify that the brake controller is sending a signal to the trailer brakes when the brake pedal is pressed.
- Adjust the brake controller’s sensitivity setting according to the trailer’s weight and the road conditions.
- Perform a low-speed test in a safe area to ensure the brakes are functioning properly.
Step 10: Final Inspection
- Double-check all wiring connections to ensure they are secure and well-insulated.
- Verify that all nuts and bolts are properly torqued.
- Inspect the brake assemblies for any signs of leaks or damage.
- Make sure the brake controller is properly calibrated.
Frequently Asked Questions (FAQs)
FAQ 1: What size electric brakes do I need for my trailer?
The size of the electric brakes needed is determined by your trailer’s Gross Axle Weight Rating (GAWR). Check the trailer’s VIN plate or manufacturer’s specifications for this information. Select brake assemblies that are rated for at least half of the GAWR per wheel.
FAQ 2: What is the difference between a time-delayed and a proportional brake controller?
A time-delayed brake controller applies the trailer brakes after a set delay, regardless of how hard you press the tow vehicle’s brake pedal. A proportional brake controller, on the other hand, applies the trailer brakes in direct proportion to the tow vehicle’s braking force. Proportional controllers are generally smoother and more responsive.
FAQ 3: How do I properly adjust electric trailer brakes?
Adjust electric trailer brakes by turning the adjustment star wheel until the shoes drag slightly against the drum. Then, back off the adjuster a few clicks until the wheel spins freely with minimal drag. Consult your brake assembly’s instructions for the exact procedure.
FAQ 4: What gauge wire should I use for electric trailer brakes?
12-gauge wire is the most common and generally recommended size for electric trailer brakes. However, consult your brake controller’s and brake assembly’s instructions for specific requirements, especially for longer wiring runs.
FAQ 5: How do I troubleshoot electric trailer brake problems?
Common problems include weak braking, uneven braking, or no braking at all. Use a multimeter to check for voltage at the brake assemblies when the brake pedal is pressed. Check wiring connections for corrosion or damage. Ensure the brake controller is properly connected and calibrated.
FAQ 6: How often should I inspect and maintain my electric trailer brakes?
Inspect your electric trailer brakes at least once a year, or more frequently if you tow regularly. Check for wear on the brake shoes, grease the bearings, and inspect the wiring for damage.
FAQ 7: Can I install electric brakes on a trailer that originally had surge brakes?
Yes, but it requires replacing the surge brake actuator with a standard trailer coupler. You will also need to install the electric brake assemblies, wiring, and a brake controller.
FAQ 8: What are the signs of worn-out electric trailer brakes?
Signs of worn-out electric trailer brakes include reduced braking performance, squealing noises, and excessive brake dust on the wheels.
FAQ 9: What is “brake fade” and how can I prevent it?
Brake fade is the temporary loss of braking power due to overheating of the brake components. To prevent brake fade, avoid excessive braking, especially on long downhills. Use a lower gear to help control your speed.
FAQ 10: Do I need to lubricate electric trailer brakes?
Yes, you need to grease the wheel bearings regularly to ensure smooth operation and prevent damage. You may also need to lubricate the brake shoe pivot points. Consult your brake assembly’s instructions for specific lubrication recommendations.
FAQ 11: What should I do if my trailer brakes lock up?
If your trailer brakes lock up, immediately release the tow vehicle’s brake pedal. Then, gradually reapply the brakes to avoid skidding. Adjust the brake controller’s sensitivity setting to reduce the likelihood of lockup.
FAQ 12: Is it legal to tow a trailer without working brakes?
Towing a trailer without working brakes is illegal in most jurisdictions and extremely dangerous. Always ensure your trailer brakes are functioning properly before towing. Consult your local laws for specific requirements.
By following this comprehensive guide and addressing the frequently asked questions, you can confidently install electric trailer brakes and enhance the safety and control of your towing experience. Remember to always prioritize safety and consult with a qualified professional if you are unsure about any aspect of the installation process.