Monoblock Forged Caliper
One-piece aluminum body for high rigidity and minimal flex under hard rear-axle load.

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Mono EMB4 Rear Wheel 4-Piston Big Brake KitMono Series Rear Axle Monoblock Forged BBK Mono EMB4 Rear 4 Piston Big Brake Kit The Mono EMB4 is a rear axle big brake kit engineered to balance a front upgrade with stable bias, clean pedal modulation, and repeatable stopping power. A 4 piston monoblock forged aluminum caliper drives 30 mm pistons against 28 mm two piece rotors sized 345, 355, or 380 mm with steel or carbon ceramic options to match your build. Why Builders Choose the EMB4 Monoblock
Mono Series · Rear Axle · Monoblock Forged BBK
The Mono EMB4 is a rear-axle big brake kit engineered to balance a front upgrade with stable bias, clean pedal modulation, and repeatable stopping power. A 4-piston monoblock forged aluminum caliper drives 30 mm pistons against 28 mm two-piece rotors sized 345, 355, or 380 mm — with steel or carbon-ceramic options to match your build.
One-piece aluminum body for high rigidity and minimal flex under hard rear-axle load.
30 mm × 4 pistons, 28.3 cm² total piston area per caliper for even pad loading.
Two-piece pistons reduce heat transfer from pad to fluid, helping pedal feel during repeated stops.
Sized to pair with a larger front BBK without overpowering the rear axle.
Three rotor diameters and 18 in+ wheel clearance for a wide range of fitments.
| Brake Caliper | ||
|---|---|---|
| Series | Mono Series | |
| Model / Application | EMB4 | |
| Axle Position | Rear | |
| Piston Count | 4-piston | |
| Piston Type | Two-piece heat-insulated pistons, no dust boots | |
| Piston Diameter | 30 mm × 4 | |
| Total Piston Area | 28.3 cm² per caliper | |
| Caliper Dimensions | L 268 × W 164 × H 68 mm | |
| Manufacturing Process | Monoblock forged aluminum body | |
| Net Weight | 2.55 kg per caliper, without pads | |
| Surface Finish | Nickel-plated | |
| Recommended Wheel Size | 18 in or larger | |
| Recommended Rotor Size | Ø345–380 mm × 28 mm | |
| Brake Rotor Options | ||
| Rotor Option | Steel (Option A) | Carbon-Ceramic (Option B) |
| Rotor Material | Heat-treated high-carbon cast iron | Carbon-ceramic composite |
| Axle Position | Rear | Rear |
| Rotor Dimensions | Ø345 / 355 / 380 mm × 28 mm | Ø380 mm × 28 mm |
| Construction | Two-piece assembly | Two-piece assembly |
| Ventilation | Internally vented | Internally vented |
| Rotor Mounting | Fixed or floating, by rotor size & application | Floating |
| Directional Design | Yes — left/right specific | Yes — left/right specific |
| Rotor Face Pattern | Curved slot / Grain slot / Wave slot / Drilled & slotted | Cross-drilled |
| Brake Pad Options | ||
| Pad Option | For Steel Rotors | For Carbon-Ceramic Rotors |
| Compatible Rotor Material | Iron / steel rotors only | Carbon-ceramic rotors only |
| Operating Temperature Range | 0–600 °C | 0–700 °C |
| Average Friction Coefficient | μ ≈ 0.38 | μ ≈ 0.45 |
| Lines | ||
| Brake Line Construction | Three-layer construction | |
| Brake Line Material | PTFE inner liner / SUS304 stainless braid / PVC outer sheath | |
| Brake Line Function | Reduces line expansion for a firmer pedal | |
| Brake Line Fittings | Vehicle-specific on caliper and chassis sides | |
| Brackets | ||
| Rotor Hat Manufacturing Process | CNC-machined | |
| Rotor Hat Material | High-strength aluminum alloy | |
| Caliper Bracket Manufacturing Process | CNC-machined | |
| Caliper Bracket Material | Carbon steel | |
| Caliper Mounting Type | Radial mount with vehicle-specific brackets | |
| Fitment & Installation | ||
| Minimum Spoke Clearance | 101 mm | |
| Recommended Wheel Size | 18 in or larger | |
| Rotor Diameter Selection | 345, 355, or 380 mm, selected according to vehicle application and wheel clearance | |
| Bedding-In Procedure | Required before aggressive driving | |
Friction varies with temperature, line pressure, and rotor condition. Always match pads to rotor material.
Two EMB4 rear calipers.
Matched pads for both rear calipers.
Two-piece rotors in your selected size and material.
CNC carbon-steel vehicle-specific brackets.
CNC aluminum hats.
Stainless braided lines.
Confirm wheel inner-barrel clearance, rotor diameter, and vehicle application before ordering. Use the included template or contact us with your wheel and vehicle details.
18 in or larger wheels are required.
The EMB4 requires at least 101 mm spoke clearance. Larger rotors and certain wheel designs may require more clearance.
Confirm rotor size, bracket availability, brake line fittings, and rear brake bias for your vehicle before ordering.
It is designed to balance a larger front BBK and deliver clean rear bias without overpowering the chassis.
Rear-axle only. It is designed to balance a larger front BBK and deliver clean rear bias without overpowering the chassis.
Steel rotors come in Ø345, 355, or 380 mm × 28 mm. Carbon-ceramic is offered in Ø380 mm × 28 mm. All are two-piece, internally vented, and directional.
18 in or larger, with at least 101 mm spoke clearance. Larger rotors and certain wheel designs may require more clearance — verify with a fitment template.
No. Pads are compound-specific. Use iron/steel pads on steel rotors and CCB-spec pads on carbon-ceramic rotors only.
Two EMB4 rear calipers, two-piece rotors in your selected size and material, matched pads, stainless braided lines, CNC aluminum hats, and CNC carbon-steel vehicle-specific brackets.
Yes. A proper bed-in transfers an even pad layer to the rotor face, which is critical for bite, modulation, and long-term rotor life.
Need help confirming wheel clearance, rotor size, or bracket availability for your vehicle?