12/07/2010
In the dynamic world of automotive engineering, braking systems are continuously evolving, pushing the boundaries of safety, convenience, and performance. From the sophisticated electronics governing modern parking brakes to the high-octane compounds designed for the racetrack, understanding these innovations is key for any enthusiast or professional. This article delves into two significant advancements: the Electronic Parking Brake (EPB) caliper and the revolutionary HPS brake pads, offering insights into their technology, benefits, and crucial considerations.
The Electronic Parking Brake (EPB) Caliper: A Modern Marvel
Gone are the days of manually yanking a handbrake lever. The Electronic Parking Brake (EPB) has become a staple in many modern vehicles, offering a sleek, convenient, and often safer alternative. At its heart lies the EPB brake caliper, a sophisticated component that forms the backbone of this electronic system.
Unlike traditional calipers that rely solely on hydraulic pressure from the foot pedal, the EPB brake caliper is uniquely equipped with an additional electric motor. This motor is the true innovation here. When the driver activates the EPB (usually via a button on the dashboard or centre console), the electric motor springs into action. It precisely operates the electronic parking brake by putting direct pressure on the pistons via a transmission mechanism. This, in turn, applies firm pressure to the brake pads, clamping them against the brake discs and effectively holding the vehicle stationary. Essentially, it acts as the EPB's fundamental operational element.
How EPB Calipers Enhance Your Driving Experience
- Convenience and Ergonomics: The most immediate benefit is the elimination of the traditional handbrake lever, freeing up interior space and offering a cleaner cabin aesthetic. Activation is typically a simple press or pull of a button.
- Automatic Engagement/Disengagement: Many EPB systems automatically engage when the ignition is turned off and disengage when the driver presses the accelerator (with the seatbelt fastened), preventing accidental roll-back and simplifying hill starts. This feature is often referred to as 'hill-hold assist'.
- Enhanced Safety: In an emergency, some EPB systems can be used as an auxiliary braking system, applying all four brakes for a controlled stop, even at speed. This is a significant safety upgrade over a mechanical handbrake which typically only acts on the rear wheels.
- Reduced Effort: No more straining to pull a stiff handbrake lever; the electric motor does all the work.
- Consistent Braking Force: The electronic control ensures a consistent and optimal clamping force, regardless of the incline or vehicle load, which can be difficult to achieve with a manual lever.
Maintenance and Considerations for EPB Systems
While highly beneficial, EPB systems do introduce new considerations for maintenance. Changing brake pads on an EPB-equipped vehicle often requires specific diagnostic tools to retract the caliper piston electronically before new pads can be fitted. Attempting to force the piston back manually can damage the electric motor or the gearing mechanism, leading to costly repairs. Therefore, professional servicing by technicians with the appropriate equipment is highly recommended for any brake work involving EPB calipers.
| Feature | Electronic Parking Brake (EPB) | Traditional Parking Brake |
|---|---|---|
| Activation | Button/Switch (Electric Motor) | Lever/Pedal (Mechanical Cable) |
| Space Usage | Minimal (Button only) | Requires console space for lever |
| Hill-Hold Assist | Commonly Integrated | Manual operation required |
| Emergency Braking | Controlled 4-wheel braking (if equipped) | Rear-wheel only, prone to skidding |
| Maintenance | Requires diagnostic tools for pad changes | Generally simpler, no special tools |
| Cost of Repair | Potentially higher due to complexity | Generally lower |
The Cutting Edge of Performance: HPS Brake Pads
For those who push their vehicles to the limit, particularly on the track, standard brake pads simply won't suffice. This is where high-performance compounds, like those from HPS (High Performance Store) and their collaboration with EBC, come into play. After years of dedicated research and development, EBC, recognised as the world's largest motorcycle brake pad manufacturer, has introduced a groundbreaking sintered compound that has truly redefined track-only performance.
The feedback on these pads, particularly the EBC GPFAX compound, has been nothing short of stellar. As renowned Nürburgring Nordschleife lap record holder Andy Carlile succinctly puts it, 'These things are brilliant.' He praises the optimal level of feedback, allowing precise control by varying lever pressure until the front tyre and fork springs provide the desired ground push. This superior feel translates directly into confidence and control on the track, earning a perfect 10/10 for feel.
Unrivalled Retardation and Performance Characteristics
The retardation (stopping power) delivered by these pads is so exceptional that Carlile was able to revert to lighter 'Wavy discs' without any compromise in stopping performance. This highlights the pad's efficiency and ability to generate immense friction, even with less disc surface area.
The HPS/EBC GPFAX pads boast an impressive array of features designed specifically for the demanding environment of competitive racing:
- Instant Unbeatable Stopping Power: Crucially, these pads deliver incredible stopping force even from cold, a significant advantage over many race pads that require considerable warming up to reach optimal performance.
- Extreme High Temperature Fade Resistance: On the track, brakes are subjected to immense heat. These pads are engineered to maintain their performance under extreme temperatures, ensuring consistent and reliable braking without significant fade resistance.
- Superb Feel and Feedback: As highlighted by top racers, the precise feedback at the brake lever allows for unparalleled control and modulation, critical for shaving off milliseconds on lap times.
- Wide Compatibility: They are compatible with both original equipment and aftermarket steel discs, offering versatility for various setups.
- Racer Validated: Fully pre-launch tested by racers and track riders across all skill levels, ensuring their real-world effectiveness.
- Minimal Bedding-In: These pads are 'quickly usable', requiring only a minimal bedding-in process, which means more time on track and less time preparing.
- Low Wear and Abrasion: Despite their aggressive performance, they exhibit the lowest pad wear and disc rotor abrasion levels, contributing to component longevity.
- Consistent Friction: Minimum 'in-stop' friction/retardation variation ensures predictable and stable braking throughout the entire braking manoeuvre.
A Critical Warning: Not for Road/Street Use
It is absolutely paramount to understand that the HPS/EBC GPFAX compound is explicitly designed for race-only compound use on closed circuits. The extremely high friction levels delivered by this compound are intended for use with race tyres only. Using these pads on public roads or low-adhesion road surfaces is unsuitable and highly dangerous. Furthermore, their use will invalidate road insurance as they are NOT ECE R 90 approved nor TUV tested with German ABE, making their use on the public highway illegal in many countries.
These high-performance pads are not to be confused with EBC's regular Road Performance ‘Double-H’ or GPFA Race pads, which are designed for different applications. If you are unsure about suitability, HPS offers specific guidance and even a 14-day money-back guarantee on your first set (excluding postage) if you follow their advice and don't find them to be the best race pads you've ever used.
Frequently Asked Questions
About EPB Brake Calipers:
- Q: Can I manually release an EPB if the battery dies?
- A: Most vehicles with an EPB system have a manual release procedure as a backup, typically involving a tool or a specific sequence. However, this varies significantly by manufacturer, and it's always best to consult your vehicle's owner's manual.
- Q: What happens if an EPB system fails?
- A: Modern EPB systems are designed with built-in redundancies. If a fault occurs, a warning light will illuminate on the dashboard. In some cases, the brake may remain engaged or disengaged. It's crucial to seek professional diagnosis immediately if an EPB fault occurs.
- Q: Is it more expensive to replace EPB brake pads?
- A: The pads themselves may be similar in cost to conventional pads, but the labour cost for replacement can be higher due to the specialised tools and diagnostic equipment required to retract the calipers safely.
About HPS Brake Pads:
- Q: What does 'bedding-in' mean for brake pads?
- A: Bedding-in is the process of gently heating and cooling new brake pads and discs to transfer a thin, even layer of friction material from the pad to the disc. This optimises performance and prevents premature wear or noise. HPS/GPFAX pads require minimal bedding-in.
- Q: Why are HPS/GPFAX pads not suitable for road use?
- A: They generate extremely high friction, which can lead to over-braking and tyre lock-up on street tyres, especially on low-adhesion road surfaces like wet tarmac. They also lack regulatory approval for public road use in many regions, making their use illegal and voiding insurance.
- Q: How long do high-performance brake pads like HPS/GPFAX last?
- A: While HPS/GPFAX pads boast low wear rates for a race compound, their lifespan is highly dependent on track conditions, braking style, and the intensity of use. They are designed for maximum performance, not necessarily maximum mileage, unlike road-specific pads.
Conclusion
The evolution of braking technology continues to enhance both the safety and performance aspects of our vehicles. The EPB brake caliper represents a significant stride in convenience and integrated safety for everyday driving, simplifying the parking brake function and adding intelligent features. Conversely, high-performance brake pads like the HPS/EBC GPFAX compound push the limits of stopping power and control, catering specifically to the extreme demands of track use. Understanding the distinct purposes and limitations of these advanced components is vital, ensuring that you always choose the right braking solution for your specific needs, whether for daily commutes or chasing lap records on a closed circuit.
If you want to read more articles similar to Mastering Your Stops: EPB & HPS Brakes Unpacked, you can visit the Brakes category.