Why Do Audi S5 Brakes Squeak?

Audi S5 brakes most often squeak because of high‑performance brake pad materials, surface glazing, light corrosion or dust on the discs, lack of lubrication at pad contact points, or worn components such as pads and anti-rattle hardware; in many cases the noise is annoying but not dangerous, though persistent or loud squealing should be inspected to rule out wear or defects.

How the Audi S5 Braking System Creates Noise

The Audi S5 uses performance-oriented braking components designed to deliver strong, repeatable stopping power at high speeds. That performance bias comes with a trade-off: higher likelihood of squeaks and squeals, especially at low speeds or light brake pressure. Understanding how the system works helps explain why noises are common even on relatively new cars.

Performance Brakes and Their Trade-Offs

On many S5 models, especially those with the S-line or performance packages, Audi specifies aggressive pad compounds and large ventilated discs. These are optimized for heat resistance and bite under spirited driving, not silent operation in city traffic. As a result, a certain amount of brake noise is considered “normal” by both Audi and many owners, particularly in cool, damp weather or after the car has sat overnight.

Most Common Reasons Audi S5 Brakes Squeak

Several overlapping factors can cause squeaking on an Audi S5. Some are entirely harmless, while others indicate maintenance is due or something is wrong. Pinpointing which scenario applies usually requires listening for patterns: when the noise occurs, how loud it is, and whether it changes with use or weather.

1. High-Performance Brake Pad Material

The most frequent culprit is the brake pad compound itself. The S5 typically uses semi-metallic or low-metallic pads from the factory. These are durable and handle high temperatures well, but they’re more prone to noise than the softer, comfort-focused pads used on many non-performance models.

The main ways pad material contributes to squeaking include:

• High metal content: Hard metallic particles can vibrate against the rotor at high frequency, producing a squeal.
• Cold friction characteristics: Some performance pads grip less smoothly when cold and can squeak until warmed up.
• Low-speed modulation: When braking lightly—such as creeping in traffic or parking garages—the pad may not fully “seat” against the disc, increasing vibration and noise.

In these cases, the pads are doing exactly what they were designed to do for performance driving, and the squeak is an acoustic side effect rather than a safety concern.

2. Surface Rust and Moisture on the Brake Discs

Another everyday source of squeaks is light corrosion on the rotors. Steel brake discs rust quickly when exposed to rain, road salt, or humidity—sometimes in just a few hours of sitting outdoors.

Corrosion and moisture affect brake noise in several ways:

• Light surface rust: The first few brake applications scrape the rust away, causing a gritty, high-pitched squeal or scraping sound.
• Overnight condensation: Early-morning braking often sounds louder, then quiets down after several stops.
• Seasonal effects: In winter or in coastal climates, owners frequently report more brake squeal due to constant moisture and salt exposure.

If the squeaking disappears after a few normal stops—especially after rain or washing the car—it’s usually just surface rust and not a mechanical problem.

3. Brake Dust Buildup and Pad Glazing

Performance pads generate significant amounts of brake dust. Over time, this dust can accumulate on the pad and rotor surfaces, especially if the car is driven in stop‑and‑go traffic, with little hard braking to clean the surfaces.

This buildup can lead to two related issues:

• Dust packing into the pad surface: Compact dust can create uneven friction, increasing high-frequency vibration that sounds like a squeal.
• Glazed pads or rotors: Repeated light braking or riding the brakes can overheat the top layer of the pad, creating a hard, shiny (glazed) surface that squeaks under light pressure.

In many cases, a few strong, safe stops from moderate speed or a proper brake service (cleaning and deglazing) can reduce or eliminate these noises.

4. Lack of Lubrication on Contact Points

Even with good pads and clean rotors, brakes can squeak if the hardware isn’t lubricated correctly. The pads must be able to move smoothly within the caliper bracket, and the caliper slide pins must operate freely.

Common lubrication-related issues include:

• Dry or corroded pad backing plates: If no high-temperature brake grease is applied to the back of the pads and to the abutment (contact) points, metal-on-metal vibration can cause squeal.
• Sticking caliper pins: Dry or seized slide pins prevent the pads from retracting evenly, leading to light drag and noise.
• Improper assembly after brake jobs: If anti-squeal shims or grease were omitted during a pad replacement, squeaks often appear shortly afterward.

A proper brake service—cleaning, lubricating contact points with the correct grease, and ensuring all hardware is installed—often resolves these types of squeaks.

5. Worn Pads, Rotors, or Hardware

While many S5 brake squeaks are benign, some indicate that parts are wearing out and need replacement. Modern pads include wear indicators that are deliberately designed to squeal loudly when the pad material is nearly gone.

Wear-related noise can appear in several forms:

• Pad wear indicators: As the pad wears down, a small metal tab begins touching the rotor, producing a sharp, continuous squeal that gets worse with braking.
• Grooved or ridged rotors: Deep grooves in the brake discs cause the pads to vibrate and can make a chirping or squealing sound every time the brakes are applied.
• Loose or fatigued hardware: Worn anti-rattle clips or shims can allow the pads to chatter, especially over bumps or during light braking.

Any new, persistent squeal—especially if it gets louder over time—should be inspected to rule out normal wear reaching its limits or hardware failure.

6. Driving Style and Conditions

An Audi S5 driven mostly in city traffic will have a different brake noise profile than one that regularly sees highway or spirited driving. How and where the car is used can meaningfully affect squeaks.

Typical patterns related to use and environment include:

• Stop-and-go city driving: Frequent light braking encourages dust buildup and glazing, both of which increase squeaks.
• Long, gentle braking: Riding the brakes on downhills or slowing gradually from high speed without firm stops can overheat the pad surface and promote glazing.
• Climate and road conditions: High humidity, frequent rain, road salt, and cold temperatures all increase the likelihood of squeals, even on otherwise healthy brakes.

Adjusting driving habits—such as applying firm, controlled braking from time to time—can sometimes reduce how often the brakes squeak.

Distinguishing Normal Squeaks From Problems

Not every squeak means the brakes are failing. However, it’s important to know when noise is simply a characteristic of a performance system and when it signals the need for attention.

When Squeaking Is Usually Harmless

Some forms of brake noise are considered acceptable for the S5’s performance-oriented setup, particularly if they appear in specific, predictable situations.

Squeaks are often benign when they:

• Occur briefly after the car has been parked in wet or humid conditions and fade after a few stops.
• Happen mostly at very low speeds with light pedal pressure, especially in parking lots or slow traffic.
• Are mild, intermittent, and don’t grow steadily worse over days or weeks.

In these situations, the squeak is typically a side effect of pad design, minor rust, or dust, and the brakes can still be functioning safely and effectively.

Warning Signs That Need Inspection

Other types of noise or changes in brake feel can signal a problem that requires prompt inspection by a qualified mechanic or Audi specialist.

Seek professional attention if you notice:

• A loud, continuous squeal or screech that starts suddenly and doesn’t go away.
• Grinding noises, especially if they sound like metal scraping metal.
• Vibration, pulsation, or a shudder in the steering wheel or pedal when braking.
• Increased brake pedal travel, a “spongy” pedal, or reduced stopping power.
• Uneven pad wear or noticeably grooved/blue-tinted rotors on visual inspection.

Persistent or worsening symptoms like these can indicate worn-through pads, warped rotors, sticking calipers, or other issues that affect safety and should be addressed quickly.

How to Reduce or Eliminate Squeaking on an Audi S5

While some level of brake noise may be inevitable on a performance car, there are practical ways to reduce squeaks without compromising safety. The best approach depends on whether you prioritize quiet operation or maximum performance.

Service and Maintenance Steps

Routine and targeted brake servicing often solves many squeak complaints, especially after aftermarket pad changes or prolonged city driving.

Typical maintenance strategies include:

• Professional brake inspection: Checking pad thickness, rotor condition, hardware, and caliper operation.
• Cleaning and deglazing: Lightly machining or sanding glazed rotors and pads, and removing accumulated dust and rust.
• Lubricating contact points: Using high-temperature brake grease on pad backs, shims, and slide points—without contaminating friction surfaces.
• Refreshing hardware: Replacing worn anti-rattle clips, shims, and pins to restore proper pad fit and reduce vibration.

These steps are often included in a comprehensive brake service and can significantly cut down on non-critical squeaks.

Choosing the Right Brake Pads

If noise is a top concern and you are not tracking the car or driving aggressively on a regular basis, changing pad type can make a substantial difference. However, it nearly always involves a trade-off between ultimate performance and comfort.

Pad selection considerations include:

• Comfort-oriented ceramic pads: Typically quieter, with less dust, but may have slightly less initial bite and different pedal feel compared with OEM performance pads.
• Street-performance pads: Designed to balance low noise with improved friction; some are formulated specifically to reduce squeal on European performance cars.
• OEM vs aftermarket: Genuine Audi pads are tuned to the car’s braking system and stability control, but some premium aftermarket brands offer quieter alternatives that still work well on the S5.

Consulting a trusted technician or brake specialist who understands Audi platforms can help you choose a pad that fits your driving style and noise tolerance.

Adapting Driving Habits

Small changes in how you use the brakes can also influence squeak frequency, especially if your S5 spends much of its time in urban or light-duty use.

Helpful driving adjustments include:

• Occasional firm stops: From a safe speed on an empty, straight road, a few strong, controlled brake applications can clean light rust and dust and help prevent glazing.
• Avoiding riding the brakes: Using engine braking on long descents and applying firm, brief brake pressure rather than long, light pressure reduces heat and glazing.
• Warming the brakes: In very cold conditions, expect more noise until the pads and rotors reach operating temperature, especially on performance compounds.

These habits won’t eliminate all squeaks but can lessen many of the conditions that make them more frequent.

Summary

Audi S5 brake squeaks are commonly caused by the car’s performance-oriented pad materials, surface rust or moisture on the rotors, brake dust and glazing, insufficient lubrication at pad contact points, or normal wear of pads, rotors, and hardware. Many of the noises—especially brief squeals after rain or during light, low-speed braking—are characteristic rather than dangerous. However, persistent, loud squealing, grinding, or changes in braking feel warrant a professional inspection.

Owners can often reduce squeaks through proper brake servicing, using appropriate high-quality pads, ensuring hardware and lubrication are correct, and adopting driving habits that minimize glazing and buildup. In the end, some level of noise is a typical compromise on a high-performance car like the S5, but excessive or changing noise should never be ignored.

Why do German cars brakes squeak?

Due to the friction of the brake pads against the rotors, they’ll wear down over time. As a result, it can cause loud noises when they grind against one another. When you start to hear this, it’s time to make an appointment to have your vehicle’s brake pads replaced.

Why are my Audi brakes squeaking?

Audi brake squeaking is often caused by brake dust accumulation from their performance brake pads, worn brake pads, or lack of lubrication between components. Other causes include surface rust, debris, improper installation, or manufacturing issues. 
Common causes

• Brake dust: Audi’s high-performance, semi-metallic brake pads create more dust. This buildup of dust, dirt, and road chemicals can cause squeaking, especially with new brakes. 
• Worn brake pads: As brake pads wear down, a chamfer (tapered edge) is removed, which can cause vibrations and noise. Worn pads may also have a wear indicator (a small metal clip) that squeals to alert you of a needed replacement. 
• Lack of lubrication: Insufficient lubrication on the back of brake pads or where the pads contact the caliper can cause friction and squeal. 
• Debris and rust: Dirt, dust, or rust on the brake rotors can cause squeaking noises when they are rubbed by the pads. 
• Improper installation: If components aren’t installed correctly, it can lead to friction and noise. 
• Glazed pads or rotors: A hard or glazed surface on either the pads or rotors from excessive heat can create an annoying squeal. 
• Cold weather: Moisture and cold temperatures can sometimes cause temporary squeaking when you first start driving. 

What you can do

• Hard braking: If the noise is from dust on new brakes, a few hard stops can sometimes clean the pads and rotors enough to stop the squealing. 
• Clean components: Use a high-quality brake cleaner to remove dust and debris between the caliper and disc. 
• Lubricate: Apply high-temperature brake lubricant to the edges of the brake pads and any other contact points as recommended by your service advisor. 
• Inspect for wear: If you consistently hear squealing, have your brake pads inspected for wear. A low-pitched grinding is a sign of metal-on-metal contact, which is a more serious issue. 
• Check with a professional: If the squeaking persists, a certified Audi technician can diagnose the problem, especially if there’s an issue with installation or a manufacturing defect. 

This video demonstrates how to clean the brake components and apply lubricant: 56sGreaseMonkeyTVYouTube · Dec 19, 2020

Why are my brakes squeaking but brakes are fine?

Brakes can squeak even when they have good pad life due to issues like glazing, contamination, or improper lubrication and installation. Glazing can occur from hard or constant braking, while dirt, debris, or surface rust can get trapped between the pad and rotor. Lack of proper lubrication or incorrect installation, like using cheap hardware or missing anti-squeal shims, can also cause vibrations that lead to squealing. 
This video explains the causes of brake squeaking and how to identify them: 59sHumbleMechanicYouTube · Mar 14, 2020
Common causes

• Glazed rotors or pads: Repeated or heavy braking can create a shiny, smooth surface on the rotors and pads, which can cause them to squeal. This is often fixed by driving to “burn it off” or by lightly sanding the surface. 
• Dirt and debris: Road salt, dirt, or other contaminants can become lodged between the pad and rotor, causing a squeaking or grinding noise. It is important to remove the wheels and clean the brakes thoroughly. 
• Lack of lubrication: The metal-on-metal contact points between the brake pads and the caliper, as well as the caliper guide pins, need to be properly lubricated to prevent sticking and vibration. Without this, the pads can get stuck or the caliper can’t move freely, leading to squealing. 
• Improper installation: If components like shims, hardware, or the pads themselves are installed incorrectly, they can cause unwanted friction and noise. This can happen even with new parts if the installation is not done correctly. 
• Rust: After rain or when a car sits for a while, light surface rust can form on the rotors, causing squeaking. This usually goes away after the first few stops. If it persists, it may indicate a more serious problem. 

You can watch this video to learn how to fix squeaky brakes: 15smilanmastracciYouTube · Jan 21, 2016
What to do

• Clean the brakes: A good cleaning can remove dirt and debris. You can use a stiff brush with soap and water or a brake cleaner spray, being careful not to spray the brake pad material. 
• Lubricate the brake components: Apply a high-temperature lubricant to the metal-on-metal contact points and slider pins. 
• Check for proper installation: Ensure all components, including the anti-squeal shims, are in place and the pads are installed correctly. 
• Consult a professional: If the squeaking persists, a mechanic can properly diagnose the issue, which may include resurfacing or replacing the rotors or pads. 

What is the Audi Squeaky brakes lawsuit?

Plaintiffs Valeria Mercado and Andrea Kristyanne Holmes claim the Audi Q7 squeaking front brakes are distracting to Audi drivers and others on the roads. The initial class action lawsuit included 2015-2018 Q7 SUVs, but the settlement includes only 2017 and 2018 SUVs.