Adjusting trailer brakes is crucial for safe towing, ensuring your trailer stops reliably and prevents accidents. This process involves tightening the brake shoes until they lightly drag on the brake drum or rotor, ensuring adequate stopping power while preventing premature wear.
Why Trailer Brake Adjustment Matters
Properly adjusted trailer brakes are not merely a suggestion; they are a safety imperative. Neglecting this maintenance task can lead to a multitude of problems, including:
- Reduced stopping power: This is the most obvious and dangerous consequence. Poorly adjusted brakes can significantly increase stopping distances, potentially leading to collisions.
- Uneven braking: This can cause the trailer to swerve or pull to one side during braking, making it difficult to control and increasing the risk of jackknifing.
- Premature brake wear: Brakes that are too loose won’t engage fully, causing them to wear down faster. Brakes that are too tight can overheat and damage the linings and drums/rotors.
- Increased fuel consumption: Dragging brakes increase rolling resistance, forcing your tow vehicle to work harder and burn more fuel.
- Damage to brake components: Overheating can warp rotors, score drums, and damage other brake components, leading to costly repairs.
Before undertaking any adjustments, consult your trailer’s owner’s manual for specific recommendations and specifications. Different trailer types and brake systems may have unique adjustment procedures. This guide provides a general overview, but the manual is your primary source of information.
Tools You’ll Need
Before you begin, gather the necessary tools:
- Jack and jack stands: To safely lift and support the trailer.
- Lug wrench: To remove the wheels.
- Brake adjustment tool (brake spoon): A specialized tool for turning the brake adjuster wheel. (A flat-head screwdriver can sometimes work, but a brake spoon is recommended).
- Wheel chocks: To secure the trailer and prevent it from rolling.
- Gloves: To protect your hands.
- Safety glasses: To protect your eyes from dust and debris.
- Torque wrench: To properly tighten the lug nuts after reinstallation.
- Penetrating oil (optional): To loosen any rusted adjuster wheels.
- Brake cleaner (optional): To clean brake components.
- Owner’s manual: Containing specific instructions for your trailer.
Step-by-Step Adjustment Process (Manual Adjustment)
This section details the manual adjustment process commonly used for drum brakes. If your trailer has electric brakes, consult your manual for specific electric brake controller adjustment procedures. While disc brakes are often self-adjusting, inspection is still vital.
1. Safety First
- Park the trailer on a level surface.
- Engage the parking brake on the tow vehicle.
- Chock the wheels of the trailer on the opposite side of the wheels you’ll be adjusting.
2. Lifting the Trailer
- Using a jack, lift the trailer until the wheel you’re adjusting is off the ground.
- Securely support the trailer with jack stands placed under the frame. Never work under a trailer supported only by a jack.
3. Removing the Wheel
- Use the lug wrench to loosen the lug nuts on the wheel.
- Completely remove the lug nuts and carefully remove the wheel.
4. Locating the Adjustment Slot
- On the backing plate of the brake assembly, you’ll find an oval or rectangular adjustment slot. This slot is usually covered by a rubber or plastic plug.
- Remove the plug to access the brake adjuster wheel. If the plug is missing, you might need to use penetrating oil to loosen the adjuster wheel, which may have accumulated rust and debris.
5. Adjusting the Brakes
- Insert the brake adjustment tool into the slot.
- Turn the adjuster wheel. The direction you need to turn it depends on the type of brake assembly. Typically, you’ll turn it upward to tighten the brakes. Listen for a clicking sound as the star wheel rotates.
- Tighten the brakes until the wheel is difficult to turn by hand. The brake shoes should be dragging lightly against the drum.
- Back off the adjuster wheel a few clicks until the wheel spins freely with only a slight drag. This ensures the brakes are properly adjusted without being overly tight.
6. Reinstalling the Wheel
- Carefully reinstall the wheel onto the hub.
- Tighten the lug nuts by hand in a star pattern.
- Lower the trailer until the wheel just touches the ground.
- Torque the lug nuts to the manufacturer’s specifications using a torque wrench.
- Completely lower the trailer and remove the jack and jack stands.
7. Repeating the Process
- Repeat steps 2 through 6 for each wheel that needs adjustment.
8. Testing the Brakes
- After adjusting all the brakes, conduct a test drive in a safe area.
- Start at a slow speed and gradually increase it, applying the trailer brakes gently.
- Pay attention to how the trailer feels during braking. It should stop smoothly and evenly, without pulling to one side.
- If you notice any problems, re-inspect and adjust the brakes as needed.
Understanding Electric Brakes
Electric brakes use an electromagnet to activate the brakes. The brake controller in your tow vehicle sends an electrical signal to the trailer brakes, activating the electromagnets which then pull on the brake shoes. Properly adjusting the brake controller is just as important as adjusting the physical brakes themselves. Consult your brake controller’s manual for specific instructions. Ensure that the controller is properly calibrated for the weight of your trailer and that the gain is set appropriately.
Frequently Asked Questions (FAQs)
Here are some frequently asked questions regarding trailer brake adjustment:
Q1: How often should I adjust my trailer brakes?
A: It’s recommended to adjust your trailer brakes every 3,000 miles or every year, whichever comes first. More frequent adjustments may be necessary if you tow frequently or in harsh conditions. Also, check them before any long trip.
Q2: How do I know if my trailer brakes need adjusting?
A: Signs that your trailer brakes need adjusting include: increased stopping distance, uneven braking, a spongy brake pedal, and noticeable brake drag. You might also hear grinding or squealing noises coming from the brakes.
Q3: Can I adjust trailer brakes myself, or should I take it to a professional?
A: If you’re comfortable working on vehicles and have the necessary tools, you can adjust your trailer brakes yourself. However, if you’re unsure or lack experience, it’s best to take your trailer to a qualified mechanic. Brake work is critical to safety and improper adjustments could lead to accidents.
Q4: What is a brake spoon (adjustment tool) used for?
A: A brake spoon is a specialized tool designed to rotate the star wheel adjuster inside the brake drum. It provides better leverage and access than a standard screwdriver, minimizing the risk of damaging the adjuster mechanism.
Q5: What is “brake drag,” and why is it important to avoid?
A: Brake drag occurs when the brake shoes are constantly rubbing against the drum or rotor, even when the brakes are not applied. This can cause overheating, premature wear, and reduced fuel efficiency. Proper adjustment eliminates excessive drag while ensuring sufficient braking force.
Q6: What should I do if I can’t turn the brake adjuster wheel?
A: If the adjuster wheel is stuck, try applying penetrating oil to the mechanism and letting it soak for a while. You can also gently tap the backing plate with a hammer to help loosen any rust or debris. If it still won’t budge, you may need to disassemble the brake assembly for further inspection and cleaning.
Q7: What is the difference between manual and self-adjusting trailer brakes?
A: Manual brakes require periodic manual adjustment as described above. Self-adjusting brakes automatically adjust themselves to compensate for wear. However, even self-adjusting brakes should be inspected regularly to ensure they are functioning correctly.
Q8: My trailer has disc brakes. Do they need adjustment?
A: While most disc brakes are self-adjusting, it’s still important to inspect them regularly for wear, damage, and proper operation. Check the brake pads for sufficient thickness and the rotors for cracks or excessive wear. If you notice any problems, have them serviced by a professional.
Q9: What is a breakaway system, and how does it work?
A: A breakaway system is a safety feature that automatically applies the trailer brakes if the trailer becomes disconnected from the tow vehicle. It consists of a cable attached to the tow vehicle and a switch on the trailer. If the trailer separates, the cable pulls the switch, activating the trailer brakes. Always check the breakaway system before each trip.
Q10: What happens if my trailer brakes are adjusted too tightly?
A: Overly tight trailer brakes can lead to overheating, brake fade, premature wear, and even brake lockup. This can be dangerous, especially at high speeds.
Q11: Can I upgrade my trailer brakes?
A: Yes, you can upgrade your trailer brakes. Common upgrades include switching to electric over hydraulic brakes for increased stopping power or installing disc brakes for better performance and reliability. Consult with a trailer specialist to determine the best upgrade for your needs.
Q12: What is “brake fade,” and how can I prevent it?
A: Brake fade is a temporary reduction in braking power caused by overheating of the brake components. It can be prevented by proper brake adjustment, avoiding excessive braking, and using lower gears on steep descents. Upgrading to higher-performance brake components can also help reduce the risk of brake fade.