Trailer Brakes

Whether you're adding brakes onto your trailer, replacing old ones, or upgrading for better stopping power, we can provide the trailer parts that you need to support your job done right. Having brakes on your trailer is a must. Many people require brakes on trailers of a certain size in order to be street legal, and there are plenty of good reasons for that. In addition, to keep you and others on the road safe, brakes help keep your cargo safe by providing an improved, more controlled ride. Getting the best possible braking setup for your trailer will also help eliminate wear and tear on both your trailer and your tow vehicle, saving you a lot of money in the long run.

How does a trailer brake work?


Does one thing that always concerned you? When you drive through large cities and over mountain passes, how do the brakes on your trailer work? Cargo trailers, utility trailers, boat trailers, camper trailers – there are a ton of different trailer types, and it’s important to know how to slow down and stop when towing any kind of trailer.

Disc brakes are composed of a hub and rotor a caliper, and a mounting bracket. The trailer caliper, which is positioned around the trailer hub and trailer rotor, includes a piston and brake pads, one pad on each side of the rotor. When you activate your truck brakes, the force of your vehicle against the actuator creates hydraulic pressure inside the master cylinder in the actuator, just like with hydraulic drum brakes. This pressure sends brake fluid through the brake line to the piston in the caliper. The piston extends and pushes the backing plate of the inner brake pad, which then squeezes the rotor. The friction created by the brake pads squeezing the rotor slows down the trailer.


Disc brakes are known for providing more consistent stopping, and more stopping power in general, than drum brakes. This means they reduce your stopping distance so you'll be less likely to jackknife or collide with another vehicle should you have to slam on your brakes. And because of their design, disc brakes are very well vented. This is why they don't experience brake fade as often as drum brakes. Because of their self-contained design, disc brakes don't retain any excess water, which not only prevents corrosion, but also makes them function a lot better when wet. This makes them a very popular choice for frequent boaters. However, the price often stops people from making the decision to go with disc brakes over drum. Even though disc brakes don't require as much maintenance, they're considerably more expensive to purchase outright.

Refurbishing Brake Calipers on your caravan or boat trailer can be an expensive exercise when caliper pistons seize, a problem particularly common on boat trailers due to excessive exposure to corrosive environments. Of course, there are solutions and suggestions for ongoing maintenance, however, first, we must understand the underlying problem. Suppliers manufacture calipers in Dacromet or Stainless steel versions for Australian boat trailers.

Electric over hydraulic actuators pump hydraulic oil to the brake caliper. This hydraulic oil pressure varies from 1000 psi to 1600psi depending on the weight of the trailer and the size of the brake actuator. During braking, the hydraulic oil activates the caliper piston as it enters the cylinder chamber thereby pushing the piston onto the brake pads which in turn causes friction on the disc rotor. This friction causes braking. The more pressure applied by the brake controller, the stronger the braking.

The trailer brake pistons


Caliper pistons are manufactured of phenolic plastic, aluminum, or steel. “Phenolic” refers to a variety of hard plastic that is exceptionally strong and heat resistant. Phenolic pistons reduce heat transfer into the brake fluid, resist corrosion that could cause caliper binding, and are lightweight.

Whilst it is true that phenolic pistons resist corrosion, they are known to scratch over time and can also sit for long periods. As a result, the hard plastic material becomes hygroscopic.

The plastic material is actually phenolic resin. This high-strength man-made material has several advantages over steel brake caliper pistons. The first advantage is corrosion resistance. The material will not react with water and salt and rust. But, if the brake fluid is acidic, it can damage the piston over time. The second advantage is heat resistance. The phenolic piston will not transfer as much heat to the brake fluid when compared to steel pistons.

When the engineers design the brake system they design the system with the piston material and brake pad in mind. The package of the piston, shim, backing plate, and friction material are engineered together. If the original caliper piston was phenolic, the replacement caliper needs to have a phenolic caliper.

The one thing that can cause a failure of a phenolic or steel piston is a damaged piston boot. If the boot is missing, torn or not properly seated on the caliper or piston, corrosion on the surface or dirt caked on the surface of the piston, will scrub back and forth on the piston bore seal every time the brakes are applied and released. Before long, the seal will lose its ability to hold pressure and the caliper will start to leak brake fluid.