Maximum Clamp Force for the Most Demanding Explorer ST Builds
The RFK.640.03 Rotora Street Challenge Front Brake System is built for 2020-2023 Ford Explorer ST owners who demand maximum front braking performance. An 8-piston RF806 forged caliper paired with a 380x35mm 2-piece floating rotor delivers exceptional clamping force and heat management for the Explorer ST builds that push hardest.
Key Features
- 8-piston RF806 forged aluminum caliper for maximum clamping force
- 380x35mm 2-piece floating rotor for increased swept area and heat capacity
- Direct bolt-on fitment for the front axle, no permanent modification required
- Available in 10 caliper finishes including Natural Anodize (Zinc)
- Slotted or Drilled rotor face options to match braking preference
- Stainless steel braided brake lines included for firmer pedal feel
- Performance brake pads matched to the RF806 caliper included
- Built for the most demanding street and track driving
Fitment
| Year Range | Make | Model | Trim |
|---|---|---|---|
| 2020-2023 | Ford | Explorer | ST |
Specifications
| Detail | Value |
|---|---|
| MPN | RFK.640.03 |
| Caliper Type | 8-piston RF806 forged aluminum |
| Rotor Size | 380x35mm |
| Rotor Type | 2-piece floating disc |
| Position | Front |
| Finish Options | 10 caliper colors, Slotted or Drilled rotor |
| Fitment | 2020-2023 Ford Explorer ST |
| Warranty | Manufacturer limited warranty |
What’s Included
- 2x RF806 8-piston forged aluminum calipers
- 2x 380x35mm 2-piece floating rotors
- Stainless steel braided brake lines
- Mounting brackets and hardware
- Performance brake pads
About Rotora
Rotora designs and manufactures big brake kits for street and track enthusiasts, engineering forged aluminum calipers and 2-piece rotors that deliver consistent stopping power under demanding conditions.
FAQ
What is the RFK.640.03?
The RFK.640.03 is a Rotora Street Challenge front brake system for the 2020-2023 Ford Explorer ST, featuring an 8-piston RF806 forged aluminum caliper and a 380x35mm 2-piece floating rotor.
How does this kit differ from the RFK.640.02?
The RFK.640.03 uses an 8-piston RF806 caliper compared to the 6-piston RF606 on the RFK.640.02, delivering greater clamping force with the same 380x35mm rotor.
What caliper colors are available?
The RFK.640.03 is available in 10 caliper finishes, including Red, Dark Metallic Blue, Silver, Gloss Black, Green, Orange, Light Metallic Blue, White, Black Hard-Anodize Finish, Yellow, and Natural Anodize (Zinc).
What is the difference between Slotted and Drilled rotors?
Slotted rotors clear gas and debris from the pad surface, while Drilled rotors add additional cooling channels through the rotor face. Both are available for this kit.
Does this kit include brake pads?
Yes, performance brake pads matched to the RF806 caliper are included with this kit.
Is this a front or rear brake system?
The RFK.640.03 is a front brake system. A matching rear system is available separately for the Explorer ST.
Will I need to modify my Explorer to install this kit?
No, this kit is designed for direct bolt-on installation on the front axle without permanent modification.
What is the rotor construction on this kit?
The RFK.640.03 uses a 380x35mm 2-piece floating rotor design for reduced rotational weight and improved heat dissipation.
Install Instructions
- Lift the vehicle and secure it on jack stands, then remove the front wheels.
- Remove the factory front calipers and disconnect the brake lines.
- Remove the factory front rotors and brake hardware.
- Install the new 380x35mm 2-piece floating rotors onto the front hubs.
- Mount the RF806 8-piston calipers using the supplied brackets and hardware.
- Install the included performance brake pads into the calipers.
- Connect the new stainless steel braided brake lines and torque all fittings.
- Bleed the brake system thoroughly and check for leaks.
- Reinstall the wheels, torque to spec, and bed in the new brakes before hard driving.
WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.








