Stop It!


Photo Credit: Bob Livingston

by Bill and Jenn Gehr
July 28, 2016
Filed under Products, Reviews, Top Stories


On fifth-wheels and travel trailers, upgrading from electric to Kodiak disc brakes shortens stopping distances dramatically


It’s no secret that trailers and fifth-wheels are getting bigger. And with that extra length comes a full list of standards and options. Add larger slideouts, deeper storage compartments and extra-large garages, and the load grows exponentially. Tow vehicles may be able to pull these heavy, homelike RVs, but efficient — and safe — braking could be an issue, considering the limitations of the trailer’s electric brakes. Upgrading a trailer or fifth-wheel with disc brakes shortens stopping distances substantially. Kodiak Trailer Components is one of the major suppliers of kits designed to retrofit the electric brakes that are commonly used on trailer chassis.

 If you’ve ever experienced brake fade or brake failure with electric brakes, you know that sinking feeling in your stomach when it’s difficult to stop or slow down, especially during emergency braking. Unfortunately, the standard electric drum brakes have not kept up with the times, and the best brake-lining material, asbestos, was banned years ago, leaving more environmentally friendly but less effective shoe material to perform an even more extreme-duty job.

Disc brakes have fewer moving parts that more effectively dissipate heat, and the calipers are self-adjusting, unlike most electric brakes, eliminating unequal braking on either side of the axle, which results in much better performance. Another important factor to consider when deciding on the benefits of a conversion is that disc brakes are less affected by water or rust and are extremely fade-resistant for those long downhill grades, which is ideal for anyone towing a heavy RV.

It is smart to consider what type of traveling you will be doing, now and in the future, before deciding on the disc-brake conversion kit that will be best for your RV. Kodiak offers various disc-brake conversion kits that are manufactured with several different types of materials and coatings. The company offers kits made of stainless steel for the ultimate protection from moisture and salt, and a number of coatings that bridge the gap be­tween standard parts and stainless steel. The company’s Dacromet and e-coatings are designed for all types of climates that an RV might live in, including coastal areas where rust is a serious problem. Even areas with high humidity can wreak havoc on moving parts, so the materials are very important.


The HydraStar actuator employs a simple four-wire system using standard RV wire color code.


When installing the actuator in a storage compartment, be sure to use cable clamps to secure the brake lines to avoid any type of damage.


When installing the actuator in a storage compartment, be sure to use cable clamps to secure the brake lines to avoid any type of damage.


During the caliper bleeding process, it’s important that the actuator does not run out of brake fluid. Air will enter the brake lines, and you will have to start over again.


When starting the bleeding process of the brake lines, always begin at the farthest caliper from the actuator.


Before installing the new hub and rotor assemblies, clean the spindle and inspect for flaws or damage. Replace any parts that may be compromised.


Install the Kodiak caliper flanges to the axle flange, torquing to the manufacturer’s specifications.


During installation of the hub and rotor assembly, be careful not to damage the spindle or threads.


Install the outer bearing, making sure that it fits into the race properly. If the bearing does not fit properly, remove the hub and reseat until the proper fit is achieved.


Install the spindle nut to the manufacturer’s specifications.


Insert the cotter pin to prevent the spindle nut from loosening.


Be careful not to overtighten the plastic dust cap. If the cap is overtightened, failure is eminent.


Carefully install the calipers onto each rotor.


Use the supplied bolts and torque to the manufacturer’s specifications.


Calipers fitted with new brake pads can be quite snug when installing them onto the rotor. Carefully tap the bottom and the top of the caliper until it seats into the proper position.


In our case, the caliper would not fit over the flange because of excess material. A hand grinder was used to remove just enough material to ensure the proper fit.


Use a box end wrench to start the caliper mounting bolts, as this will give you more control than using a heavy-duty socket and ratchet assembly.


High-quality brake lines and fittings offered by Kodiak are designed to last a long time in trailer service.


High-quality brake lines and fittings offered by Kodiak are designed to last a long time in trailer service.


During removal of the electric brake backing assembly, be careful not to damage the grease seal surface, spindle or threads.


Before using the brakes, the air must be bled from the brake lines. A hose is pushed onto the bleeder fitting at the caliper, and the other end is submerged into a clear container with fresh brake fluid.


Before installing the tires and wheels, carefully inspect the installation of all parts and brake lines. One small missed step can cause brake failure.


Before installing the tires and wheels, carefully inspect the installation of all parts and brake lines. One small missed step can cause brake failure.

Kodiak’s kit components include coated rotors to minimize corrosion between the rotor hub face and the wheel face. Kits with stainless-steel pistons, ceramic brake pads and brass bleeding fittings are integral for a solid, rust-free system designed to last the lifetime of an RV and are well worth the cost of admission.

Unlike electric brakes, hydraulic disc brakes require an electric-over-hydraulic actuator. This piece of equipment routes the pressurized hydraulic fluid via a signal from the brake controller to the calipers in response to braking of the tow vehicle. HydraStar’s hydraulic trailer brake actuator was our choice for powering the two 8,000-pound-rated axles on the test fifth-wheel trailer with the Kodiak disc brakes.

 HydraStar offers three hydraulic actuators for small to large brake calipers. All three are designed to work with most OEM integrated brake controllers as well as most aftermarket brake controllers. Model HBA-16 is rated at 1,600 psi and has possibly the fastest response time and shortest stopping distance in the industry; it meets all DOT and federal requirements. Compact in size at only 11.8 inches long, 3 inches wide and 7.3 inches high, this unit has a large fluid reservoir essential for bleeding the system and pressurizing four or more large brake calipers without losing critical volume. For integrated brake controllers that are not compatible, HydraStar offers an HBA-CAM adapter.

Installation of the Kodiak disc brakes and HydraStar actuator is time-consuming but pretty straightforward; figure on around six to eight hours, if you are an experienced DIY mechanic. The process begins with selection of the brake actuator’s location, keeping in mind that the shorter the brake lines to the calipers, the faster the response time.

The only choice for locating the actuator in the test Carriage Cameo 36-foot fifth-wheel was in the front compartment, slightly more than 16 feet from the front axle. The batteries were close, making it easier to supply a positive and negative wire to the actuator. All of the other wires needed to complete the HydraStar installation were also close at hand. Directions for wiring are very precise.

The next step is to lift all four tires off the ground and support the chassis with properly rated jack stands. After the tires and wheels are removed and set aside, the wires are cut, and the hub/drum and backing-plate assemblies are removed.

Once the old brake components are clear, it’s time to install the caliper mounting brackets, paying close attention to the position of each one: three o’clock on the left side and nine o’clock on the right side. The hub and rotor assemblies install fairly easily, although we had to do some grinding on the bracket to make everything fit perfectly. We then spun the rotors several times to ensure they moved freely and rechecked the spindle nut for proper tightness, according to the manufacturer’s specifications.

When installing the calipers, the fluid-bleed fitting must point up, and the mounting bolts are torqued to 40 to 50 lb-ft.

 Some preplanning is required to route the brake lines, which, along with the necessary fittings, are included with the kit. Getting the brake lines from the actuator to the axles will require custom routing, and it’s important to provide enough slack in the lines to allow for any axle flexing while on the road. All of the brake lines will be permanently mounted and will need to be protected from rocks or debris that can be thrown from the tires.

After double checking all of the brake-line connections, we filled the HydraStar actuator reservoir with DOT 3 brake fluid and followed the directions for bleeding the air from the system. This process starts at the brake caliper farthest from the actuator, using the bleeder fitting on the caliper. It’s best to use a small, clear vinyl hose and a clear bottle filled partially with fresh brake fluid to capture the fluid and air being pushed out of the system. This allows you to see when the bubbles stop, indicating that the air is purged from the brake line.

To complete the bleeding procedure, you will need a helper to activate the tow vehicle’s brake controller, which will engage the HydraStar actuator and pressurize the brake lines. We used the hands-free speakers on our cell phones to communicate during this process rather than relying on a walkie-talkie, which needs to be manually activated.

When the actuator is running with the bleeder fitting open, count out five to 10 seconds, then close the bleeder and stop the brake control. Repeat this process with the other three calipers. It’s a little tricky, but very important, so be patient. Be sure to fill the fluid reservoir continually throughout this process and triple check all fittings for possible brake-fluid leaks — and wear safety glasses, as brake fluid is not something you want in your eyes.

If you allow the actuator to go dry, you’ll have to start over.

Reinstall the tires and wheels, and you’re ready for the road. Before driving at normal speeds on public roads, manually test the brakes for function while moving forward slowly. Be sure to check the lug nuts and brake lines after the first 50 miles and then again after the next 50 miles.

Ideally, new brake pads and rotors need a short break-in period for maximum performance. For the first 2 or 3 miles, try to avoid heavy braking, which leads to higher rotor temperatures. Start driving with four or five moderate braking stops from 40 mph while manually applying the brake control. Let the brakes cool for 20 to 30 minutes. Next, complete four or five more aggressive braking stops from 40 mph. Again, let the brakes cool for 20 to 30 minutes.

After the break-in period, we towed the 17,000-pound fifth-wheel on various roads and steep grades, and the overall performance of the Kodiak disc brakes was astounding compared to the electric counterparts. The powerful feeling of being able to descend long, steep grades with confidence and peace of mind made the towing experience much more enjoyable. Once you’ve experienced disc brakes, you’ll never own a trailer with electric brakes again.

Retail prices for the Kodiak kits vary, depending on axle size and coatings, but the standard kit for two 8,000-pound axles runs around $1,100. HydraStar trailer brake actuators sell for $599.

Kodiak Trailer Components | 817-284-5141 |

HydraStar | 812-655-4544 |


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