Electric Over Hydraulic Trailer Disc Brake Conversion Reality Check

Sudden stops and steep downhill grades are the nemeses of RVers who tow trailers. Even if our reaction times and braking skills are up to the challenge, the weakest link in any stopping action is the trailer’s factory installed brake system.

Upgrading to a better trailer brake controller can improve the experience, but not by much. After nine years of full-timing, we learned about a different system that could give us more peace of mind when braking. That’s when we purchased an electric over hydraulic trailer disc brake conversion.

Slumgullion Pass, Colorado.

Why factory-installed brakes aren’t good enough

Electric drum brakes are the default system for all but the most high-end towable RV trailers. In a perfect world, here’s how the system works:

• The driver taps the brake pedal.
• An electrical signal goes through the trailer brake controller and back to the trailer wheels.
• An electromagnet on the brake assembly reacts to the signal and causes the brake shoes to expand and create friction on the brake drum.
• The trailer slows and stops.

Triple towers need better brakes.

For starters, drivers must constantly fine-tune the trailer brake controller for smoother stopping power across different driving conditions. In addition, over time and use, the electric brake magnets heat up and cool down. This repetition causes the magnet to lose some of its magnetic properties. This explains why trailer owners are always fine-tuning the brake controller; it’s a chore to get the braking to feel correct. In addition, as brake shoes wear out trailer owners must manually adjust those too.

Finally, electric drum brakes have many moving parts, making the system more complex and expensive to maintain. Disc brakes, on the other hand, have one moving part.

When we purchased a larger, heavier fifth wheel, we wanted more out of our RVing experience. Research on iRV2 Discussion Forums revealed what many other trailer owners have discovered after opting for an electric over hydraulic disc brake conversion:

“I will never have another 5ver with drum brakes again. The stopping power [with disc brakes] is incredible compared to the drum brakes. And yes I kept my drum brakes fully serviced and adjusted as I am an Auto Tech.” – wowlites iRV2 Forums Member

Pros of an electric over hydraulic trailer disc brake conversion

Hydraulic drum brakes became the standard in the 1920s, generating 400 to 500 pounds of braking pressure. The 1960s brought power assist to hydraulic drum brakes generating up to 800 pounds of braking pressure.

Hydraulic over electric disc brake conversion on a fifth wheel.

Today, with hydraulic disc brakes, they generate 1500 to 1800 pounds of braking pressure. The automotive industry has made huge advancements in stopping distances, but not so in the trailer industry, according to Ronald Russel, president of Performance Trailer Braking.

“We are still generating 1920s braking pressure with electric drum brakes generating 500 to 600 pounds of pressure,” says Russel.

Although many big rigs, luxury towables, motorcycles and even bicycles have dumped their old braking systems in favor of disc brakes, the towable industry is still 99 percent drum brakes, he explained.

Once you experience RVing with electric over hydraulic trailer disc brakes you’ll feel as if you were driving a regular passenger vehicle. That’s because this system utilizes the same disc brake technology found on today’s passenger vehicles to help your RV slow down and stop. Just like your car or truck, there is no adjustment necessary on disc brakes. “Set your gain and go,” says Russel, “There is no need to continually adjust the controllers gain.” Here’s how it works:

1. The driver presses the truck’s brake pedal.
2. An electric signal is sent to the trailer’s brake actuator.
3. The signal prompts the actuator to deliver hydraulic fluid pressure to the brake calipers, smoothly slowing down the trailer in unison with the tow vehicle.

The only downside is the cost. An electric over hydraulic trailer disc brake conversion is about $3,000 if you hire a mechanic for installation.

This system has fewer parts than electric drum brakes and maintenance is minimal enough for the average RVer who can turn a wrench.

The only downside is the cost: an electric over hydraulic trailer disc brake conversion is about $3,000 if you hire a mechanic for installation. You’ll save about half if you can do this relatively simple job yourself.

Last winter, we converted our 27-foot Arctic Fox fifth wheel’s brakes and put them to the test. We drove from Quartzsite down to the Texas Big Bend, then east to Houston and migrated north through New Mexico. As a grand finale, we drove Colorado’s Slumgullion Summit, which rises to 11,530′ elevation and features a 9 percent grade—the steepest one on any continuously paved road in the state.

Thousands of miles and many mountain passes later, we can say without a doubt that our old standard electric trailer drum brakes could never match the performance of our new disc brakes. The difference between the two systems is startling.

Now, instead of cringing whenever we stop, I smile and know that as we saved up for this major investment (we spent a little more than $2,800), it was worth the penny-pinching. The peace of mind we get from our electric over hydraulic trailer disc brake conversion is priceless.

Rene Agredano

Rene Agredano and her husband, Jim Nelson, became full-time RVers in 2007 and have been touring the country ever since. In her blog, Rene chronicles the ins and outs of the full-timing life and brings readers along to meet the fascinating people and amazing places they visit on the road. Her road trip adventures are chronicled in her blog at LiveWorkDream.com.