General Motors and Navistar considered offering an air brake system on their Medium Duty Class 4, 5, and 6 trucks – the Chevrolet Silverado Medium Duty Chassis Cab Trucks and International CV, GM Authority exclusively uncovered thanks to insider sources familiar with future GM truck programs.
The air brake system was originally considered for the 2019 Chevrolet Silverado 6500HD, which currently is the range-topping model in the Silverado Medium Duty range. However, the duo ended up deciding against offering the feature on the vehicles for the time being. Instead, the feature will be reserved for the as-of-yet rumored but unconfirmed Class 7 truck that we have reported the duo to be exploring.
The current 2019 Chevrolet Silverado Medium Duty truck line comes with a hydraulic brake system with four-channel ABS from Bosch/Meritor/Wabco. However, the rumored Class 7 Silverado will likely include air brakes as exclusive equipment for the range-topping model.
For those not intricately familiar with the difference between hydraulic and air brakes, here’s a quick rundown: the vast majority of vehicles produced today are equipped with a hydraulic brake system, which uses brake fluid to squeeze brake drums or rotors with a friction material, like a brake pad or brake shoe. By comparison, air brakes use compressed air to transmit the braking force to the pad or shoe.
Air brakes are primarily used in large commercial vehicles, and are considered preferable to a hydraulic setup for such applications. Not only are air brakes less prone to overloading when slowing heavy-weight vehicles, but they are also more reliable and easier to service, especially as a large system. While brake fluid can leak out and drain away, air is abundant and ever-present, providing an inherent fail-safe. What’s more, an air brake system doesn’t require bleeding like a hydraulic system. For that reason, they would be perfect in a potential Class 7 truck from GM and Navistar.
The current Chevrolet Silverado Medium Duty truck line was developed in conjunction with Navistar, and includes the Silverado 4500HD (Class 4), Silverado 5500HD (Class 5), and Silverado 6500 HD (Class 6) models for GM, along with Navistar’s version – the International CV. The models were jointly developed by GM and Navistar, while Navistar handles production of both variants.
Last year, GM Authority exclusively reported that GM and Navistar were exploring a possible collaboration for a new Class 7 truck, which would sit at the top of the Chevrolet Silverado range with a Gross Vehicle Weight Rating (GVWR) between 26,000 and 33,000 pounds (11,794-14,969 kilos). Our intel told us that the new Class 7 truck will launch in 2022 and come with the new air brake system, among other exclusive features.
This latest rumor follows several other firsts reported by GM Authority, including that the Silverado Medium Duty truck line will receive a new gas engine option in the near future. This new engine will likely be variant of the 6.6L V8 L8T introduced in the 2020 Chevrolet Silverado HD and 2020 GMC Sierra HD. In May, we also reported that GM is looking to expand the Silverado Medium Duty line by adding a new 22.5-inch wheel option to create a dock-height version of the work truck.