Trailer Brakes Made Simple: How They Work, Types, and How to Choose
The type of brakes fitted on a trailer play a crucial role in ensuring optimum towing performance and on-road safety. As they control the stopping capacity of your trailer, having the right brakes fitted also helps to reduce strain on your towing vehicle, improve stopping distances and prevent accidents.
If you’re buying a new trailer, understanding how the different types of trailer brakes function can ensure you make an informed decision, and that you choose trailer brakes that are appropriate for the loads you carry and compliant with state and federal road regulations —in accordance with South Australian towing regulations, any trailer with a gross trailer mass (GTM) over 750 kg must be fitted with brakes.
In this blog, or team will look at how trailer brakes work, the different options available, and how to ensure you make the right choice for your towing needs.
How trailer brakes work
Trailer brakes synchronise with the braking system on the towing vehicle; when pressure is applied to the brake pedal in the vehicle, either a mechanical or electrical signal is sent to the trailer brakes, which then apply friction to the rims.
Mechanical trailer brakes
With mechanical trailer brakes, cables connect the trailer brakes to the hitch. As the towing vehicle slows down, the trailer’s momentum activates an override mechanism and the brakes are engaged.
Mechanical disc brakes with calipers will usually be sufficient for smaller trailers (up to a GTM of 2 tonnes) that are primarily used for towing light loads. However, upgrading from mechanical to hydraulic disc brakes can significantly improve stopping power in all types of conditions.
Electric trailer brakes
With electric trailer brakes, a controller in the towing vehicle sends an electrical current to the magnets in the trailer hubs, which expand the brake shoes and creates the friction required to slow the trailer.
Electric brakes offer the greater control that is required for larger tandem and tri-axle trailers that are used for carrying heavier loads. They are operated via a controller in the towing vehicle from which the braking force can be adjusted.
In South Australia, trailers with a GTM in excess of 2,000kg must have electric brakes that are fitted with a breakaway system. This will automatically apply the trailer brakes if it becomes separated from the towing vehicle, ensuring not only your safety but the safety of other road users too.
Trailer brake safety and maintenance
Regardless of the types of trailer brakes you have fitted, proper synchronisation between the trailer and towing vehicle is essential. This will ensure that trailer momentum does not push the vehicle forward when braking, especially important on uneven or steep terrain, or when towing on wet or icy roads.
Regular inspection of pads, drums and cables to ensure there is no excessive wear and tear, is highly recommended to keep trailer brakes functioning at optimum capacity. Regularly cleaning components and lubricating moving parts will help to prevent corrosion, while the controller on electrical trailer brakes should also be calibrated regularly to ensure accuracy.
We also recommend testing trailer brakes regularly on a safe, quiet road to ensure ongoing responsiveness.
How to choose the right trailer brakes
When deciding what sort of trailer brakes you need to have fitted, it is important to understand the dimensions, ATM and GTM of any trailer you’re considering buying.
If you opt for a single axle trailer — such as a small box trailer, enclosed trailer, motorbike trailer or tradesman trailer — and are unlikely to be towing heavy loads, then mechanical brakes with callipers will be sufficient to ensure you are able to tow safely.
However, while larger tandem axle and tri-axle trailers with a GTM below 2,000kg can legally be fitted with mechanical brakes, electric trailer brakes are highly recommended for these larger trailer models, as they deliver greater safety and control when hauling heavier loads.
If you’re looking at a heavier trailer with a GTM over 2 tonnes, then you are required to have electric trailer brakes with a breakaway system fitted.
Need help and advice on choosing the right trailer brakes?
Understanding how trailer brakes function, and what sort of system is going to be right for the trailer and loads you carry, will ensure you are able to tow with confidence.
If you need expert assistance and advice, don’t hesitate to get in touch with the friendly, knowledgeable team at Basic Trailers. Simply email info@basictrailers.com.au, call us on 1300 770 770, or drop by our Pooraka trailer workshop and we’ll be happy to help.
