Brake pad
The brake pad is one of the most safety-critical components of any vehicle. Together with the brake disc, it converts kinetic energy into heat and ensures reliable deceleration – thousands of times over its service life. In this comprehensive guide, you will learn everything about materials, wear, replacement intervals, the influence of modern vehicle architectures (especially electric and hybrid vehicles) and how the right vehicle electronics – from the battery to the tyre pressure sensor – optimally support your brake system.
1. What is a brake pad and what is its function?
Brake pads are the friction partners of the disc brake. Their steel backplate holds the friction material, which is pressed against the rotating brake disc when the brake pedal is pressed. The resulting friction decelerates the vehicle and converts kinetic energy into heat. Modern car brake pads must withstand extreme thermal loads – temperatures of over 600 °C can occur briefly. The average friction coefficient range (µ) is between 0.35 and 0.45 depending on the compound. A constant friction coefficient over as wide a temperature range as possible is crucial to ensure safe braking even after several emergency stops (fading).
In addition to the pure braking effect, the brake pad also influences comfort factors such as noise development (squealing, juddering) and brake dust emission. Especially in high-performance or heavy vehicles, the demands on thermal stability and service life increase enormously.
2. Brake pad materials compared
Today, three main groups of friction materials dominate the spare parts market. Each has characteristic advantages and disadvantages in terms of braking effect, wear, noise and price. The optimal choice depends on the vehicle type, driving profile and personal priorities.
| Material type | Advantages | Disadvantages |
|---|---|---|
| Organic (NAO) | Quiet, low disc wear, comfortable, low dust development | Higher wear rate, lower temperature resistance, less bite in cold weather |
| Semi-metallic | High heat stability, excellent braking performance even at high speeds, good bite | Higher noise levels, more brake dust, greater disc wear |
| Ceramic (low-met / ceramic composite) | Extremely long-lasting, quiet, very little brake dust, comfortable, high fade resistance | Higher purchase price, slightly delayed cold braking performance at extremely sub-zero temperatures |
For most cars in everyday use, a high-quality semi-metallic or ceramic brake pad is a good choice. Sporty drivers or high-mileage drivers often opt for ceramic to minimise service life and cleaning effort.
3. Recognising brake pad wear: warning signals and sensors
The minimum thickness of the friction material (without the backing plate) is around 2–3 mm depending on the manufacturer and model. If the pad falls below this, metal-to-metal contact threatens, which can destroy the brake disc. Look out for the following warning signals:
- Squealing or grinding noises when braking (often caused by an acoustic wear indicator, a small metal tab that scrapes against the disc).
- Visual check: if the pad is thinner than 3 mm, a change is imminent.
- Illumination of the brake warning light in the instrument cluster, triggered by an electronic wear sensor.
- Longer braking distance or a spongy pedal feel.
- The vehicle pulling to one side when braking (can indicate uneven pad wear).
3.1. Electronic brake pad wear sensors
Many modern vehicles rely on contact-based or inductive sensors that continuously report the pad condition to the control unit. Even though Electronicx GmbH does not stock brake pad wear sensors, these systems underline the growing role of vehicle electronics for driving safety. An equally safety-relevant area is tyre pressure monitoring – correct air pressure demonstrably improves braking distance and driving stability. With our TPMS sensors you always keep an eye on tyre pressure digitally and reduce the risk of tyre blowouts, especially during emergency braking.
4. Brake pads in electric and hybrid vehicles: regenerative braking and battery influence
Electrified drives fundamentally change brake pad management. Since the electric motor(s) act as a generator during deceleration and feed kinetic energy back into the battery (recuperation), the regenerative braking system handles a large part of everyday braking work. The mechanical friction brake is therefore used up to 70% less often – a clear gain for brake pad life. In electric cars, original brake pads can therefore often achieve mileages of 200,000 km and more.
4.1. How regenerative braking protects brake pads
During a normal city drive or anticipatory driving on country roads, the electric motor does most of the braking. This massively reduces wear on the mechanical brake. Only during strong deceleration or emergency braking, and at very low speeds (below approx. 10 km/h), does the system engage the hydraulic brake. The result: fewer heat cycles, less mechanical abrasion and a significantly longer service life for the pads.
4.2. The role of the battery: capacity (Ah), voltage (V) and cold cranking current (CCA)
For recuperation to work efficiently, the traction battery (or the 12 V electrical system in mild hybrids) must be able to absorb enough energy. High-quality starter batteries and supply batteries therefore play a decisive background role – even for the braking system. Let us look at the typical technical specifications:
- AGM battery (start-stop): capacity around 70–95 Ah, voltage 12 V, cold cranking current (CCA) 720–850 A, charge cycles (according to EN 50342) > 600 at 50% depth of discharge. Price range: approx. 120–300 €.
- EFB battery: similar capacity, CCA somewhat lower (600–700 A), cycle stability roughly twice as high as a conventional flooded battery. Price: 100–200 €.
- LiFePO4 battery (lithium iron phosphate): capacity 30–150 Ah, nominal voltage 12.8 V, extremely high cycle stability (> 2000 at 80% DoD), continuous nominal current often 50–150 A, charging current up to 50 A (recommended). Price: 300–800 € depending on Ah. Such batteries are used in motorhomes or as a second battery with high energy reserves.
A powerful electrical system with low internal resistance not only supports recuperation but also ensures that electrohydraulic brake boosters and the control units (ESP, ABS) are supplied stably at all times – especially in traffic jams or during many start-stop phases. A weak battery can indirectly have a negative effect on the braking feel if assistance systems do not work correctly.
5. Brake pad replacement: intervals, costs and tools
While a replacement interval of around 30,000 to 80,000 km is typical for combustion vehicles (depending on driving style and material), electric vehicles extend this range to 120,000 to over 200,000 km. The decisive factor is always the individual wear check. The pure material costs for a set of brake pads (front or rear axle) fall within the price ranges mentioned above. The workshop costs including labour amount to around 100–300 € per axle, depending on the vehicle model and region.
If you do the work yourself, you will usually need the following in addition to the matching set of pads:
- Trolley jack and axle stands
- Ratchet, torque wrench and suitable sockets
- Brake caliper rewind tool (mechanical or hydraulic)
- Copper paste or ceramic paste for the guides
- New fastening bolts and, if applicable, sensors
- Brake fluid tester and bleeding accessories
6. Our recommendation: safety through suitable batteries and sensors
Electronicx GmbH is your partner for modern vehicle electronics. Even though we do not sell brake pads, our components ensure that your vehicle works reliably in every situation and that critical conditions are detected early. A stable power supply and precise monitoring are the basis of any brake system – especially in modern cars.
6.1. Car batteries for start-stop and hybrid systems
Especially in large cities with frequent stop-and-go, batteries have to deliver maximum performance. We supply AGM, EFB and high-performance flooded batteries free of charge within Germany by DHL – quickly and reliably. This is how to reach us:
Our free DHL shipping also applies to all other cities and regions in Germany.
6.2. TPMS sensors for optimum tyre pressure
A correctly inflated tyre ensures the shortest braking distance and protects against uneven pad wear. Direct tyre pressure monitoring systems measure each wheel precisely and warn of pressure loss.
7. Frequently asked questions (FAQ) about brake pads
How often do brake pads need to be replaced?
The rule of thumb is between 30,000 and 80,000 km for combustion vehicles. In electric cars, replacement may not be due until over 150,000 km thanks to recuperation. Regular visual inspection is decisive – at the latest when the pad is less than 3 mm thick, it should be replaced.
Which brake pad lasts the longest?
Ceramic low-met pads generally offer the longest service life, followed by high-quality semi-metallic compounds. Organic pads wear faster but are gentler on the brake discs. The actual durability is, however, strongly influenced by driving style and vehicle technology (recuperation).
What does a complete brake pad replacement cost?
At an independent workshop, the cost for one axle (including labour) is usually between 100 and 300 euros. High-priced vehicles or sports cars can be considerably higher, as larger, more expensive ceramic pads are often fitted here.
Can I replace brake pads myself?
Yes, for experienced DIY enthusiasts a brake pad replacement is feasible. Clean work, the use of a torque wrench and, if applicable, a diagnostic device to retract the electric parking brake are important. Pay attention to the brake caliper guides and bleed the system if necessary. Safety comes first – if in doubt, go to a specialist workshop.
How do I recognise inferior brake pads?
Typical signs are heavy squealing after only a short mileage, excessive brake dust, uneven pad wear or a significantly longer braking distance. Rapid discolouration of the brake disc due to heat build-up can also be an indication. Look for ECE R90 approval to ensure the minimum quality.
Does tyre pressure play a role in brake pad wear?
Indirectly, yes. Tyre pressure that is too low or uneven lengthens the braking distance and can cause one-sided or jerky braking, which increases pad wear. Direct TPMS sensors help to always maintain the ideal pressure and thus promote even wear.
Are brake pads for electric cars special?
Yes, many manufacturers use pad compounds adapted for BEVs and PHEVs that remain corrosion-resistant even after longer standing times and do not develop squealing noises when used rarely. The physical requirements are comparable, but cold braking behaviour plays a greater role, as the friction brake often only becomes active at low speeds.
Do I need new sensors with every brake pad replacement?
If your vehicle is equipped with electronic wear sensors, these should generally be replaced at the same time, as they no longer work once triggered (contact wire broken). This saves you having to dismantle everything again.
About Electronicx GmbH – your expert for electronics around the car
Electronicx GmbH, based in Cleebronn (Baden-Württemberg), specialises in high-performance car batteries (AGM, EFB, gel, LiFePO4) as well as modern TPMS sensors.
How to reach us:
Electronicx GmbHHindenburgstr. 37A
74389 Cleebronn, Germany
Telephone: +49 7135 7194106
Email: [email protected]
Managing Director: Andreas Emschanow | VAT ID: DE300176428 | HRB 752730 (Stuttgart Local Court)
For deliveries to Austria or other EU countries, please contact our support team for an individual shipping quote.