Aston Martin DB9 Brakes: Unveiling the Stopping Power

When one considers the Aston Martin DB9, the mind often conjures images of its magnificent V12 engine, the symphony of its exhaust note, and its undeniable elegance. Yet, just as crucial as its ability to accelerate with breathtaking pace is its equally impressive capacity to come to a complete and controlled stop. Indeed, the Aston Martin DB9 is equipped with a braking system that is nothing short of formidable, designed to confidently halt a vehicle weighing nearly 2 tonnes (approximately 1800 kilograms or 3,968 pounds) from high speeds. This article delves into the intricacies of the DB9's braking system, providing vital information for owners and enthusiasts alike.

While the DB9 is a luxury performance car, the good news for owners is that the fundamental principles of servicing its braking components are remarkably similar to those of many mainstream vehicles. You certainly have the option of entrusting your prized Aston Martin to a main dealership or a specialist independent garage, where qualified technicians can perform the necessary work. However, for those with a reasonable level of mechanical proficiency and a meticulous approach, many aspects of the DB9's brake system can be competently serviced at home, potentially saving a significant sum. It is paramount, however, to approach any brake work with the utmost caution and diligence.

A crucial warning must be issued here: these are your vehicle's brakes. Your safety, and indeed the safety of others, hinges entirely upon their correct function. Unlike a minor issue such as a cabin air filter replacement, errors or shortcuts when working on brakes can lead to catastrophic consequences. While comprehensive guides and resources can illuminate the correct procedures, ultimately, the responsibility for the quality and safety of the work performed rests solely with the individual undertaking it. If you have any doubts about your ability to perform the work correctly, always seek professional assistance.

It is important to note that this article focuses exclusively on Aston Martin DB9s fitted with the traditional steel rotors. The factory-optional Carbon Ceramic Material (CCM) brakes, while an incredible performance upgrade, require different assessment and maintenance techniques. If your DB9 is equipped with these advanced CCM brakes, it is strongly recommended that any service or inspection be carried out by an official Aston Martin dealership, given their specialised nature and the specific tools and knowledge required.

When to Service Your DB9 Brakes

Determining the exact frequency for brake servicing on your Aston Martin DB9 is not a one-size-fits-all answer. It is heavily influenced by your individual driving style and the quality of the brake components installed. For an owner who, for instance, attends an annual track day and uses the car as a daily driver for around 5,000 miles per year, brake pads might last approximately 15,000 miles. Brake rotors, being more robust, could potentially endure up to 30,000 miles. The handbrake pads, designed for less frequent and less strenuous use, could even last for the entire lifespan of the car.

The most effective method for knowing when your brakes require attention is through regular, diligent inspection. Developing a routine for visually checking your pads and rotors will provide you with early indicators of wear, allowing you to plan for service proactively rather than reactively, especially before warning lights appear on your dashboard.

Aston Martin DB9 Brake Specifications

The DB9's braking system is impressively proportioned, particularly by the standards of many contemporary vehicles. The fundamental role of any braking system is to convert the kinetic energy of a moving vehicle into heat, and then to efficiently dissipate that heat. The more effectively this conversion occurs, the hotter the brakes can become. Therefore, the ability to manage and rapidly dissipate this heat is crucial for consistent performance. This includes ensuring the brake fluid maintains its integrity and does not reach its boiling point, which would lead to a catastrophic loss of braking power. Under extreme conditions, such as spirited driving or track use, the DB9's brakes can reach temperatures upwards of 500°C (937°F).

Interestingly, early model DB9s (up to Model Year 2012) shared their brake components with Aston Martin Vantages. Furthermore, these specific Brembo-supplied brakes were also utilised by several other high-performance car manufacturers for models such as the Chevrolet Corvette ZR1, Chevrolet Camaro SS, Ford Shelby Mustang, and Dodge Viper. This cross-platform usage speaks to the quality and robustness of the design, and also implies a certain level of component commonality that can sometimes aid in sourcing parts.

Front Brake Specifications

The front braking system on the DB9 is engineered for maximum stopping power, bearing the brunt of the braking force. Here are its key specifications:

• Rotors:
• Diameter: 355mm (13.9 inches)
• Thickness: 32mm (1.26 inches) when new
• Material: Steel, weighing approximately 26.5 lbs (12 kg) each when new
• Design: Grooved surfaces to vent gases and dust generated under heavy braking. Internally vented for enhanced cooling.
• Calipers:
• Manufacturer: Brembo, a world-renowned brake specialist
• Pistons: 4 pistons per caliper, for even pressure distribution
• Material: Lightweight Aluminium
• Mounting: Secured with one-time use bolts – a critical detail for any service
• Pad Replacement: Designed to allow pad changes without full caliper removal

Rear Brake Specifications

While often less visually imposing than the fronts, the rear brakes play a vital role in maintaining stability and contributing significantly to overall stopping power. Their specifications are tailored to complement the front system:

• Rotors:
• Diameter: 330mm (12.9 inches)
• Thickness: 28mm (1.10 inches) when new
• Material: Steel, weighing approximately 20.5 lbs (9.3 kg) each when new
• Design: Also grooved surfaces for gas and dust venting, and internally vented for cooling.
• Calipers:
• Manufacturer: Brembo
• Pistons: 4 pistons per caliper
• Material: Lightweight Aluminium
• Mounting: Secured with one-time use bolts – again, remember this for service
• Pad Replacement: Similar to the front, pads can be changed without removing the calipers

Brake System Comparison Table

The Hand Brake System

Distinct from the primary hydraulic braking system, the Aston Martin DB9 features a completely separate mechanical hand brake. A dedicated hand brake caliper is fitted to each of the rear rotors. These are operated via a cable linked to the hand brake lever located within the car's cabin and are designed to be self-adjusting. While perfectly adequate for securing the vehicle on an incline when parked, or for executing a controlled hand brake turn, these units are considerably smaller than the main Brembo system. They are not intended for bringing the car to a stop from high speeds, though any braking capability is always preferable to none in an emergency. Servicing the hand brake system involves different procedures compared to the main brakes, which requires a specific approach.

Antilock (ABS) and Traction Control Systems

Modern high-performance vehicles like the DB9 integrate sophisticated electronic aids to enhance safety and control. The braking system works in concert with these technologies:

Antilock Brakes (ABS)

The DB9 is equipped with a four-wheel antilock braking system that is active at all times. Each wheel hub incorporates a rotation sensor and cable, which continuously monitor wheel speed. If the system detects that a wheel is about to lock up under heavy braking, it automatically modulates the brake fluid pressure to that specific wheel. This pulsation prevents the wheel from locking, maintaining it at the very verge of lock-up, which represents the maximum level of braking force without skidding. This crucial function allows the driver to retain steering control during an emergency or panic stop. When servicing the brakes, it's vital to remember that an entire ABS control system, located in the driver's side front wheel arch beneath the plastic liner, sits between the brake master cylinder and each brake caliper, influencing fluid flow and pressure.

Traction Control (TC)

Aston Martin wisely included a traction control system to manage the immense power of the V12 engine, preventing excessive wheelspin and maintaining vehicle stability. Utilising the same wheel sensors as the ABS system, traction control detects when one or both rear wheels are spinning excessively. When this occurs, the system subtly applies the rear brakes just enough to curtail the wheelspin. If you've ever accelerated hard from a standstill and felt a slight judder or seen the traction control light flash on your dashboard, that's the system at work. Consequently, aggressive driving styles that frequently trigger traction control can lead to accelerated wear on the rear brake pads compared to the fronts. For moments when one wishes to unleash the car's full, unadulterated power, the traction control (part of the Dynamic Stability Control or DSC) can be deactivated by pressing and holding the DSC button on the centre console for approximately five seconds until it illuminates. It's important to remember that while traction control can be switched off, the ABS system remains active for safety.

Brake Wear Sensors

For added peace of mind, all four wheels of the Aston Martin DB9 are fitted with brake wear sensors. The primary purpose of these sensors is to alert the driver via a dashboard warning message when the brake pads have worn down to a critically thin level, typically around 3/32″ or 2.5mm of remaining material. The sensor itself is a consumable item; it is designed with a protective surface that wears away. Once this surface is breached, it completes an electrical circuit, sending a signal to the car's computer that the pads require replacement. This intelligent system acts as a fail-safe, preventing a potentially dangerous situation if routine inspections are overlooked. When brake service is performed and the sensor has been 'worn', it must be replaced. Proactive inspection and servicing of your brakes before this warning light illuminates can often save you the additional cost of replacing the sensor.

Brake Fluid: The Unsung Hero

The Aston Martin DB9 utilises a high-performance brake fluid, a specification not typically found in standard automotive parts shops. Given the significant heat generated by the DB9's powerful braking system, the brake fluid must possess a very high 'boiling point'. If brake fluid reaches its boiling point, it creates vapour bubbles within the hydraulic lines. Unlike liquid, these gas bubbles are compressible, leading to a sudden and complete loss of brake pedal feel and, more critically, braking power – a highly dangerous scenario. Therefore, selecting the correct, high-quality brake fluid is not merely a recommendation but an absolute necessity for maintaining the integrity and safety of the braking system. It is advisable to research Aston Martin's specific fluid recommendations and explore high-performance alternatives that meet or exceed these stringent requirements.

Maintaining Your DB9's Brakes

Understanding the design and function of your Aston Martin DB9's braking system, as detailed above, is the foundational knowledge required before undertaking any maintenance or service work. While the intricacies of specific procedures for pad replacement, rotor inspection, or fluid bleeding are beyond the scope of this foundational overview, having a clear grasp of how each component functions is the first step towards ensuring safe and effective brake performance. Comprehensive guides and visual aids are invaluable resources for anyone looking to perform these tasks correctly and safely. Remember, meticulous attention to detail and adherence to manufacturer specifications are paramount.

Frequently Asked Questions (FAQs)

Q1: Are Aston Martin DB9 brakes reliable?

While Aston Martins have historically faced mixed views on overall reliability, the DB9's braking system, particularly the traditional steel setup, is generally considered robust. This is partly due to its use of high-quality Brembo components and the fact that some parts are shared with other mainstream high-performance vehicles, which can contribute to greater dependability and availability of parts compared to highly bespoke components. Regular maintenance and proper use are key to ensuring their continued reliability.

Q2: Can I service my Aston Martin DB9 brakes myself?

For owners with a good level of mechanical skill and a thorough understanding of automotive braking systems, many aspects of DB9 brake servicing, such as pad and rotor replacement, can be performed at home. However, given the critical safety function of brakes, it is imperative to follow precise procedures, use the correct tools, and ensure all components are installed correctly. If you have any doubts about your capabilities, it is always safer to entrust the work to a qualified professional.

Q3: How often should I check my DB9's brake fluid?

Brake fluid should be inspected regularly, typically during routine service intervals, to check its level and colour. Over time, brake fluid can absorb moisture, which lowers its boiling point and compromises braking performance. Aston Martin specifies replacement intervals, often every two years, regardless of mileage, due to this hygroscopic nature. Always consult your owner's manual for the precise recommended service schedule.

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