What Causes Brake Pads To Crack?

Brake pads are one of the most essential components of any vehicle’s braking system. They are responsible for providing the friction required to slow down and stop your vehicle. However, brake pads can wear down over time and develop cracks that affect braking performance. Knowing the causes of cracked brake pads can help drivers identify potential issues early and take corrective action. In this comprehensive guide, we will explore the common causes of brake pad cracking and how to address them.

Brake pads consist of a metal backing plate and friction material bonded to it. The friction material contacts the brake rotor and slows the vehicle down through friction when the brakes are applied. However, excessive heat and mechanical stress can cause the friction material to crack or separate from the backing plate. Identifying what led to cracking is the first step in resolving the issue.

Table of Contents

Common Causes Of Cracked Brake Pads

Material Defects

Manufacturing defects in the friction material composition can make brake pads prone to cracking. Inferior quality friction material that does not withstand heat and mechanical forces well can develop stress cracks. Material separation can also occur if the bonding between the friction material and backing plate is weak.

Using trustworthy brands from reputable manufacturers reduces the chances of getting defective brake pads. Sticking to original equipment manufacturer (OEM) or high-quality aftermarket pads ensures you get durable friction material that lasts.

Overheating

Excessive heat is one of the prime causes of cracked brake pads. The high temperatures caused by hard braking or brake pads getting stuck to the rotor can overheat and burn the friction material. The binding agents start breaking down, causing the material to crack or separate from the backing plate.

Managing heat is crucial to prevent overheating the brakes. Avoid riding the brakes, allow time for them to cool after hard stops, and do not ignore brake squeal or grinding noises. Proper bedding-in of new pads also reduces overheating risks.

Oil Contamination

Oil, grease or brake fluid getting on the brake pads can lead to cracking. Oil-contaminated pads have greatly reduced friction, causing them to slip and overheat. The heat dries out the oil, which then bakes into the friction material and causes cracking.

Check wheel seals, calipers, and hoses to stop oil from reaching the pads. Replace cracked pads immediately to prevent rotor damage. Thoroughly clean the brake parts to eliminate oil residue.

Underuse

Extended periods of brake pad inactivity can also cause cracking. Brake pads that do not get used regularly become dry and brittle. The binding agents and fillers in the friction material lose their plasticity. This makes the material prone to cracking from even minor stresses.

Regular brake use keeps the pads lubricated and maintains material integrity. If the vehicle stays parked for long, go on occasional drives to exercise the brakes. Replace overly dry and unused old pads.

Improper Bedding

Freshly replaced brake pads require proper bedding-in through a series of gentle stops. This transfers an even layer of friction material onto the rotors. Insufficient bedding can leave thick uneven deposits that crack off under braking pressure. It also causes vibrations and uneven braking.

Follow the bedding procedure recommended by the pad manufacturer. It typically involves accelerating to speed and braking 8-10 times from low to moderate speeds.

Mechanical Issues

Problems in caliper, slide pin or pad hardware operation can exert excessive force on the pads. Sticking or seized components either drag the pads across the rotor or press them unevenly. This abnormal wear and heat causes cracking.

Lubricate and service caliper, slide pins and pad hardware regularly. Worn parts should be replaced to ensure proper brake pad movement and avoid cracks.

Aggressive Driving

Hard braking and excessive speed generate enormous heat and mechanical stress in the brake pads. The rapid heating and cooling cycles applied through aggressive driving can overload the pads’ thermal capacity. This results in material fatigue and cracking.

Avoid sudden heavy braking when possible. Brake earlier and smoother to give the pads time to work without overheating. Moderate speed and allow cooling time after hard stops.

How To Fix Cracked Brake Pads?

Cracked brake pads become incapable of providing effective braking and should be replaced immediately. Here is a step-by-step overview of fixing cracked pads:

Inspect The Damage

Check both the inner and outer brake pads on each wheel for cracks and material separation.
See if the cracks run across the entire pad or are localized.
Note any uneven pad wear patterns indicating hardware issues.

Identify The Cause

Consider driving habits, mileage, and age to pinpoint crack causes like overheating or underuse.
Check for oil residue, uneven deposits from poor bedding, stuck components, etc.

Replace Affected Pads

Always replace pads in axle sets to retain braking symmetry.
Follow pad break-in procedure after installation to avoid re-cracking.
Flush brakes of any oil or grease contamination present.

Service Brake Hardware

Inspect caliper, slides, hardware, and rotor for issues causing uneven pad wear.
Lubricate and replace any worn components allowing abnormal pad movement.

Adjust Driving Habits

Avoid sudden heavy braking and excessive speeds to reduce pad stress.
Exercise brakes regularly if the vehicle is parked for extended periods.
Allow pads to cool sufficiently after repeated or hard stops.

Is It Safe To Drive With A Cracked Brake Pad?

No, it is extremely unsafe to drive with a cracked brake pad. Cracks compromise the structural integrity of the friction material, reducing braking performance. This increases stopping distances and the risk of brake failure.

Driving with cracked pads can also damage other brake components like rotors due to uneven contact. Small cracks quickly expand under braking pressure. To prevent accidents, cracked pads should be replaced immediately as they pose a major safety hazard.

How Do Brake Discs Crack?

Brake discs or rotors can develop cracks from overheating, mechanical stress and material defects. Excessive heat from heavy braking causes the rotor material to expand and contract repeatedly, resulting in thermal cracking. Mechanical stresses like warped rotors rubbing against the pads unevenly also create cracks.

Manufacturing impurities make some rotors prone to cracking over time. Rust corrosion from moisture creates splits. Rotors should be regularly inspected for cracks which indicate the need for replacement to avoid braking issues.

What Is The Average Life Of Brake Pads?

The average lifespan of brake pads is 20,000 to 70,000 miles depending on driving habits, vehicle type and pad material. More aggressive stop-and-go driving in urban areas shortens pad life to 20,000-40,000 miles.

Highway driving can extend it to 70,000 miles. Luxury vehicles tend to replace pads earlier at 40,000 miles due to their performance requirements. Quality ceramic pads last longer than semi-metallic and organic ones. Periodic inspection helps determine when pads need replacement.

How Can I Improve My Brake Life?

Avoiding sudden hard braking, practicing gradual stops, using engine braking, preventing overheating, regular lubrication and inspection of brake hardware, proper pad bedding, exercising brakes after long periods of inactivity, controlling exposure to oil and fluids are key ways to improve brake life. Maintaining speeds within limits, allowing pads to cool after repeated braking, and adjusting driving habits to be less aggressive also help maximize pad and rotor longevity.

When To Replace Cracked Brake Pads?

Cracked brake pads must be replaced as soon as possible to prevent potentially dangerous braking loss. Here are some specific signs to look out for:

Full-width cracks across the pad’s friction surface that are clearly visible on inspection. These affect braking across the pad’s entire contact area with the rotor.
Deep cracks and grooves that you can feel when running your fingers across the pad surface. They significantly reduce the pad’s remaining usable friction material.
Missing chunks or crumbling of the friction material due to extensive cracking and separation from the backing plate.
Loud grinding or scraping noises during braking indicating pads rubbing on the rotor unevenly due to cracks.
Uneven pad deposits on the rotor that match crack shapes and indicate poor braking surface contact.
Leaking brake fluid caused by cracked pads wearing down pistons and seals to create leaks.

Even hairline heat cracks that appear minor can quickly deepen with further use. It is advisable to replace any cracked pads as a precautionary measure before they degrade braking ability.

Preventing Brake Pad Cracking

Here are some good practices to avoid cracking and maximize brake pad life:

Avoid excessive speed and use engine braking to reduce brake usage when possible.
Brake early and gradually to give pads time to work without overheating.
Do not ride the brakes and release them fully when not braking.
Allow pads to cool sufficiently after repeated or hard braking before continuing driving.
Bed-in replacement pads properly as per manufacturer instructions.
Inspect brake fluid levels and condition regularly to prevent leaks and contamination.
Check for stuck slider pins, binding calipers or other mechanical issues during regular brake service.
Lubricate caliper pins, slides and pad abutments to ensure free pad movement.
Exercise brakes with occasional moderate stops if the vehicle is unused for extended periods.
Avoid oil, grease or fluid spills on brake components by fixing any leaks promptly.

Regular brake inspection and preventive maintenance is key to minimizing pad wear issues like cracking. Timely replacement of worn parts also ensures the braking system stays in top shape. Being proactive preserves pad friction material integrity and braking performance.

Frequently Asked Questions

Is It Safe To Drive With Cracked Brake Pads?

No, driving with cracked brake pads is extremely hazardous and should be avoided. The cracks severely compromise braking ability, increase stopping distances, and can even cause complete brake failure. Replace cracked pads immediately.

Can Cracked Brake Pads Be Repaired Or Fixed?

Cracked pads cannot be reliably repaired since the bonding between the friction material and backing plate gets damaged. The only safe solution is to replace them with new brake pads.

What Other Damage Can Occur From Cracked Brake Pads?

The compromised braking ability of cracked pads can lead to overheating and premature wear of other brake components like rotors, calipers and seals. Small cracks release brake dust that contaminates parts.

How Often Should Brake Pads Be Replaced?

With normal driving, brake pads typically last 20,000 – 70,000 miles depending on the vehicle make and model. They should be periodically inspected for wear and replaced when approaching 2-3 mm thickness.

Can I Temporarily Use Epoxy Adhesive To Fix Cracked Pads?

No, attempts to glue and repair cracked pads only offer an extremely temporary unsafe fix. The different materials and forces involved mean the cracks inevitably reappear. Pad replacement is a must.

Conclusion

Cracks and fractures in the friction material render brake pads incapable of safe and effective braking. Their ability to withstand mechanical and thermal stresses gets compromised. Identifying and addressing the root causes of cracking through inspection and maintenance is key to maximizing pad life.

Practicing gradual braking and avoiding overheating reduces pad strain. Despite preventive measures, pads subjected to extensive wear will eventually develop cracks indicating the need for replacement. Periodic checks and replacing cracked pads promptly is vital to safe vehicle operation.

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