Today’s heavy-duty trucks offer an incredible amount of hauling capability, but utilizing that capability can be intimidating for the uninitiated. Hitch class types, tongue weight, gross combined weight ratings, payload ratings, and of course maximum tow ratings must all be taken into consideration when hauling cars, boats, RVs and the like. And the bigger the load, the more crucial it becomes to ensure that you’re operating with the automaker’s defined framework.
Thankfully, some of it is pretty straight-forward if you know what the specifications of your vehicle and your equipment are. Gross Combined Weight Rating (GCWR), for example, is the maximum allowable weight of a vehicle, its passengers, cargo, and trailer, combined. Hitch classes, meanwhile, indicate the design and resulting maximum tow weight capability of a given type of tow hitch, while tongue weight is maximum allowable downward weight placed on the trailer ball itself (usually about 10 to 15 percent of the total trailer weight). That’s already more than enough to keep in mind when you’re about to hook a 30,000-pound trailer to your F-350 or Silverado 3500, but as Mark Fowler of Baer Brakes points out, that’s not the only hardware that should be taken into consideration here.
“Although the OEs have been making improvements here in recent years, it seems like factory brake systems have struggled to keep pace with the powertrain output and tow rating increases in ¾-ton trucks for a while. In many cases, it seems like the manufacturers designed these brake systems to be just good enough – there wasn’t much headroom, so to speak, when it came to stopping power. That might not be a huge issue when you’re doing normal day-to-day stuff with the truck, but it’s a much bigger concern when you’ve got 10 tons hitched to the back of your rig.”
That additional poundage inherently translates to much longer stopping distances and, perhaps even more importantly, a significant increase in the amount of heat that’s generated when braking.
“As far as the brake system is concerned, you’ve effectively increased the weight of the vehicle by 300%, or whatever the given towing situation might be,” Fowler notes. “Stopping that additional mass generates more heat, which can create brake fade in short order. And that is going to negatively impact the amount of stopping power you have to work with from one braking event to the next.”
But you don’t have to make do with a brake system that might not be up to snuff. In fact, there are several different ways to substantially improve the capability of the brake system that’s already on the truck.
Most folks think of brake pads as a maintenance item, but the truth is that the composition of the pad material can have a very noticeable effect on both brake system response and fade resistance.
“Even if you kept the factory rotors, calipers, and all of the associated hardware, just moving to a more aggressive pad than the stock ones would be an improvement,” says Fowler. “Depending on the pad compound you choose, you can increase the brake system’s initial bite at the top of the brake pedal’s travel, and you can also raise the temperature threshold of the brake system with a more purpose-built pad, which will increase the brake system’s resistance to fade in turn.”
Fowler points to Baer’s Claw line of direct-fit replacement pads as solid option for folks who’re looking to go above and beyond OE when towing with a ¾-ton truck. “Ultimately it’s about finding a balance that this customer is going to be happy with. With a normal street pad, there are a lot of concerns about brake dust, noise, and things like that. But if someone’s specifically seeking out a more aggressive pad for a more extreme use-case, you have the ability to prioritize the pad’s outright performance a bit more.”
Rotors essentially function as the brake system’s heat sink, absorbing and dissipating the heat that’s generated when the caliper clamps down on the face of the rotor during braking events. Generally speaking, the larger the rotor is, the more effectively it will function in this capacity – the bigger the disc is, the more material it has to absorb and manage that heat.
Although big brake kits typically require a substantial monetary outlay and host of new supporting hardware, Baer has created an innovative solution with the Big Claw HD line. These surprisingly affordable kits allow for a larger-than-stock rotor to be installed without requiring a revamp of the entire brake system.
“These kits include larger diameter rotors as well as a set of caliper relocation brackets that allow you to use the factory caliper with the bigger disc,” Fowler tells us. “These brackets are cast just like the factory caliper anchor bracket, but the ‘ears’ are extended to move the caliper’s position further out so it fits the larger diameter rotor.”
This not only provides are larger heat sink for the brake system, it also provides better mechanical leverage and inherently increases braking torque as compared to the factory setup.
“With this relocation kit, you’re effectively increasing the size of the ‘lever’ that’s delivering that clamping force. Think of it in the same way a breaker bar works – if you’re trying to loosen a bolt, the longer the lever is, the less effort it takes to do so. That same concept applies here. The further away you can locate the caliper out on the rotor, the more you’re increasing the lever length. The upshot is that the brake system doesn’t have to work as hard to slow the vehicle down because of that increased leverage.”
Shop Baer Big Claw HD Rotors here.
Beyond the leverage improvement and increased disc diameter, the Big Claw HD rotors also boast features you’re unlikely find on OE discs, like a directionally vaned design that functions like a centrifugal pump to provide more efficient cooling and increased resistance to fade. These high-performance discs also sport a slotted disc surface that provides an escape path for dust, gases, and other debris in order to maximize pad contact.
“These kits also retain all of the factory hardware, so it’s a true bolt-on solution – you don’t even have to bleed the brakes,” says Fowler. “So you’re getting big brake kit performance from this without the cost and involvement of a big brake kit install.”
Since this kit brings a larger rotor into the mix, it’s a good idea to make sure that this upgrade will fit your existing wheel and tire package before taking the plunge. Baer provides a free online template to make this verification process easier.
Brake controllers are a great way to refine and better define braking while towing and while some automakers are starting to offer this technology in newer heavy-duty trucks, it’s still far from standard-issue.
“If you’re outfitting your truck for towing and it didn’t come with a brake controller from the factory, it’s definitely worthwhile to go out and get one. You’re putting so much reliance on the truck’s brakes to slow that load down, so anything you can do to distribute that work out a bit more will benefit your stopping power.
This device gives you the ability to actively control the behavior of the trailer brakes when you need to. For example, if you’re coming down a hill, you can reach down and grab that brake controller Gain switch and actually use the trailer’s brakes to slow the entire load down without even touching the truck’s brake pedal. It makes a huge difference.
Read More Tow Tech: Suspension Mods For Better Towing here.
Read More Tow Tech: Tune Your Engine For Maximum Pulling Power here.
Fowler also suggests some best practices that will help to ensure that your truck’s brake system is ready for showtime.
“Fresh, high-quality DOT 4 brake fluid can make a big difference. Some folks don’t realize that brake fluid is hygroscopic, which means that it absorbs moisture in the air over time, even if the vehicle is just sitting. And as it absorbs that moisture, the boiling point of that brake fluid deteriorates. When brake fluid boils you lose hydraulic pressure, and that is going to reduce your overall stopping power. In an environment where the brakes are being taxed, fresh brake fluid will always outperform old fluid for that reason. You might not notice the difference in day-to-day driving, but when you start putting the brake system to work in extreme conditions where you’re generating a lot of heat, that’s when it really starts to matter.”
If you’ve got some questions about the best ways to outfit your heavy-duty truck’s brake system for towing, Fowler recommends reaching out to Baer’s tech line for expert advice. “This isn’t a call center with folks reading off of a script – they are brake system specialists. That’s what they do.”
Before your next long haul, make sure your brakes are ready.
