How to Disengage Trailer Brakes Safely
Towing a trailer comes with the responsibility of ensuring safe breaks. However, there may be situations where you need to disengage your trailer brakes temporarily. For example, maneuvering a trailer in reverse is easier with the brakes disengaged.
Knowing how to properly disengage your trailer brakes is crucial for safety. Improper procedures can lead to loss of control or cause brake failure. This article explains different methods to disengage trailer brakes based on brake type and provides safety tips.
Here’s a quick step-by-step guide:
- Identify your trailer brake type (surge, electric, or hydraulic).
- For surge brakes, use wheel chocks or install an anti-back up kit.
- For electric brakes, use the manual brake controller override or install a brake lockout device.
- For hydraulic brakes, use the actuator manual override or install a hydraulic lockout device.
- Always disengage brakes only when stopped and move at very slow speeds.
- Use jack stands and chocks to stabilize an unhitched trailer.
- Double check brakes are fully reengaged before towing.
Understanding Trailer Brake Systems
There are two main types of trailer brakes:
Surge Brakes utilize a master cylinder mounted to the trailer tongue that responds to inertial force. When you slow down, the trailer pushes against the hitch which applies force to the master cylinder and brake pads. No brake controller connection is needed.
Electric Trailer Brakes use magnets powered by your SUV’s brake controller to apply force to brake pads when you apply the brakes. The trailer brakes activate in sync with your SUV brakes.
Here’s a table comparing the two systems:
| Surge Brake | Electric Brake | |
|---|---|---|
| Power Source | Inertial force | Vehicle brake controller |
| Wiring | No brake controller connection needed | Needs connection to brake controller |
| Operation | Activates slightly after SUV braking | Activates simultaneously with SUV braking |
Now let’s look at how to disengage each type while backing up or maneuvering your trailer.
Disengaging Surge Brakes
Surge brakes automatically disengage when backing up since there is no inertial activation force. However, you’ll want to prevent the surge mechanism from accidental triggering during tight turns. Here are two options for keeping surge brakes disengaged:
Use Wheel Chocks
- Place wheel chocks behind the trailer tires before you unhitch.
- Leave the chocks in place when maneuvering in reverse.
- The chocks will prevent abrupt trailer movement that could accidentally activate the master cylinder.
Install a Brake Lockout Device
You can install an anti-back up kit or trailer brake lockout device. These bypass the master cylinder from responding when the trailer is in reverse gear:
- The device attaches to your backup lights’ electrical circuit.
- When you shift to reverse, it disengages trailer brakes. You maintain full brake function going forward.
- This gives you hands-free control over braking instead of relying on chocks.
Most SUVs with a trailer package already include circuits for backup lights. You can tap into the existing wiring. Make sure to use a professional installer if you aren’t comfortable working with electrical systems.
Disengaging Electric Trailer Brakes
Electric trailer brakes are not innately connected to your SUV’s transmission or backup lights. They activate based on the brake controllers signal whenever you apply your SUV brakes.
To safely disengage electric trailer brakes while reversing:
Use Your Brake Controller’s Manual Override
All brake controllers have a manual lever or button to apply the trailer brakes independently, without applying your SUV brakes. They also have a position that fully disengages the trailer brakes.
- Before backing up, set the controller to the “disengaged” position labeled “0”.
- Caution – You will have no trailer braking while using the manual override.
- Do not leave the controller disengaged during travel at road speeds.
Install an Additional Brake Lockout Circuit
You can install an electrical brake lockout device, similar to the surge brake devices covered earlier.
- When you shift to reverse, the device interrupts the signal from the brake controller to trailer brakes.
- This gives you brake control while going forward but not backing up.
- Use a professional installer if you aren’t comfortable matching colors and connecting electrical wires.
Pro tip: Another option is tapping into your backup lights’ positive signal wire to trigger a relay that interrupts the trailer brake signal.
Disengaging Hydraulic Trailer Brake Actuators
Some heavy-duty trailers use hydraulic pressure from a brake actuator instead of brake magnets. The basic concepts for disengaging hydraulic trailer brakes are the same:
- Use the manual lever on the actuator to release pressure to the brake actuators.
- Install a hydraulic brake lockout device to automatically relieve pressure when the SUV is in reverse gear.
If your trailer features spring brakes or air brakes instead of hydraulic brakes, consult a professional technician for help disengaging them.
4 Critical Safety Tips
While disengaging brakes gives you better maneuverability, it also puts you at higher risk of losing control or damaging equipment. Keep these trailer brake safety tips in mind:
- Never exceed 5 mph while operating with trailer brakes disengaged
- Avoid disengaging brakes when parked on an incline
- Use wheel chocks and jack stands to stabilize the trailer if unhitched
- Double check that trailer brakes are fully reengaged before towing on roads
Taking it slow and using extra caution is key for safety whenever you disconnect your trailer brakes.
Frequently Asked Questions
Here are answers to common questions about disengaging trailer brakes:
How do I manually release electric trailer brakes?
Use your electric brake controller’s manual override lever or button to put it in the “disengaged” position marked “0”. This interrupts the signal to the trailer brakes.
Will surge brakes work while backing up?
No. Surge brakes rely on inertial force pushing the trailer to activate. There is no inertial force applied when backing up. Surge brakes automatically stay disengaged during reverse motion.
Is it illegal to tow with trailer brakes disengaged?
Most states prohibit towing “without adequate, functioning brakes”. So you should only operate with brakes disengaged very slowly while maneuvering parked trailers. Reengage brakes before towing on roads.
Can I remove the breakaway battery to disengage electric brakes?
While removing the battery is an option in an emergency, it’s safer to use the manual brake controller override. The breakaway battery also applies brakes if the trailer uncouples, so removing it makes operation less safe if unintentionally unhitched while maneuvering.
How do I reengage trailer brakes after backing up?
Carefully follow all proper procedures for reconnecting and testing brakes outlined in your SUV and brake controller manuals. Verify functionality at low speeds before towing.
Knowing the ins and outs of your particular trailer brake setup is vital for safely disengaging and reengaging brakes when needed. When in doubt, consult an experienced towing equipment mechanic.
