Brembo Boldika Is Its Most Powerful Brake Caliper Yet

Brembo braking power and panache are not just for performance cars anymore, big heavy performance trucks and SUVs are now getting their own special Brembo treatment in the form of this innovative new six-piston caliper, the Brembo Boldika. The Italian brand claims this is its most powerful caliper to date, capable of generating 8,500 Nm of stopping force per corner. That’s 6,269 lb-ft in freedom units and it’s what you need to rein in a 4-ton truck hauling a 7-ton trailer. Its first application was the Chevrolet Silverado EV RST Stars and Steel Edition that just went on sale, and more fitments are coming.

3-Piece Mixed-Metal Design

Generating this much stopping force can induce excessive flex in traditional sliding caliper designs, which the driver perceives as less-confident pedal feel. So Brembo houses three pistons in each of two aluminum caliper halves that are bolted to a cast iron bridge that also serves as the chassis mount (via four bolts, double the traditional amount).

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Iron bridge showing four mounting holes.

What about galvanic corrosion, you fret? Program manager Ben Pohl notes, “They have to meet 10- or 15-year corrosion durability. The bracket itself is zinc/nickel coated, which is a very robust coating, so both of them have an additional layer of corrosion protection before they ever go together. And then of course we paint it, which gives another layer of protection.” On the Silverado EV, they’re painted Torch Red and wear both Chevy and Brembo badging.

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Low Drag, Easy Maintenance

The Boldika design incorporates “Brembo Enesys zero-drag” technology, a pair of springs that help the pads return to their resting position after braking to reduce residual brake torque, increasing range and maximize pad life.

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Enesys springs removed, note partial retaining pins.

Swapping pads should be a breeze as well—just remove the caliper-mounting bolts, slide the caliper off, pop out the Enesys springs, and the pads are free to fall out the middle, as the retaining pins don’t span across both halves.

20-Inch Wheel Fitment

These first Boldika calipers are designed to fit a 15.7-inch rotor inside a 20-inch wheel, but the design is easily scalable, and other heavy trucks and SUVs with differing needs are likely to adopt the design in the near future. Note that for now they’re envisioned as front brakes only, as axle-shaft endplay on the live axles on most HD pickups is better handled by sliding calipers than fixed designs like this, where pad movement can result in a mushy pedal feel. At about 31 pounds each, these calipers aren’t light, but then, they’ve got a big, worst-case-scenario job to do if your 14,000-pound trailer loses its brakes.

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Greater Confidence

Relative to other high-capacity calipers, these don't require dramatically greater hydraulic pressure or fluid displacement during normal operation, but their impressive rigidity is said to impart a very confident brake pedal feel on a loaded rig. And by pushing these extra large (20-square-inch) pads away from the rotors when they’re not in use, they’re expected to last a lot longer as well.

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HD Work Truck Fitment?

It’s unclear whether workaday trucks will adopt the Boldika. Matching the Boldika's stiffness and pedal feel with a conventional sliding caliper at these loads would likely impose significant mass and packaging penalties, but their two-piston designs are way cheaper to manufacture, rebuild, and replace, and packaging all of the caliper pistons inboard requires less clearance between the caliper and the wheel spokes. Plus, business owners and employee drivers are less likely to prioritize superior pedal feel and shiny painted design. Note that the design is also future-proofed, as it is capable of operating with Brembo’s by-wire Sensify system that uses electrohydraulic actuators at the corners.

Stay tuned for our upcoming instrumented testing of a Silverado EV Stars and Steel edition.