Understanding brake disc crazing: Insights from Comline

Staying informed about the latest developments in car parts and repair is paramount to providing a premium service. Comline, a trusted name in high-quality brake discs for the European aftermarket, has amassed a wealth of knowledge in this arena. As such Comline delves into the intriguing phenomenon of brake disc ‘crazing’.

Decoding ‘crazing’

Technicians, imagine a scenario where you are inspecting a vehicle’s brake disc and notice an unusual pattern on its surface: a cluster of small, hairline cracks resembling ‘orange peeling’ or the appearance of crazy paving. This phenomenon is what experts refer to as brake disc ‘crazing’. These clusters of cracks can vary in size and are particularly noticeable, especially on vehicles with open-style alloy wheels.

So, what’s causing it? Essentially, it’s a tell-tale sign that the brake disc has been subjected to high temperatures, indicating that the driver has been pushing their brakes to their limits, quite literally driving their brakes crazy!

Quality assurance

It’s crucial to understand that ‘crazing’ is not necessarily indicative of a quality issue with the brand of brake disc chosen for the vehicle. Instead, it’s an occurrence that affects all traditional cast metal brake discs when exposed to high temperatures. The good news is that these cracks are typically superficial and should not pose any serious issues beyond their unsightly appearance.

However, Comline emphasises the importance of a professional mechanic supporting motorists with a thorough inspection and expert diagnosis, as there are other types of cracks that can occur within a brake disc which might be more serious. Whilst cracks typically associated with crazing are largely superficial, any crack that appears to go part, or all of the way through the disc, must result in the disc being replaced immediately. Of course, safety always comes first in the world of automotive maintenance, so in the event of doubt, Comline would strongly recommend the brake disc be changed.

The ‘blueing’ effect

Sometimes, crazing isn’t the only visual indicator of high braking temperatures. Technicians may also come across the ‘blueing’ of the brake disc surface. This issue manifests as patches of the disc take on a blue tint, also in response to intense braking temperatures. Notably, it is possible to observe disc blueing without crazing.

Once again, when in doubt, technicians can provide motorists with valuable insights and recommendations based on expertise.


Understanding brake disc crazing is essential for every technician. Comline’s extensive experience in supplying high-quality brake discs sheds light on this intriguing issue, reassuring technicians that ‘crazing’ is often a benign problem related to high braking temperatures.

By staying informed and seeking knowledge from the likes of Comline when in doubt, technicians can continue to provide top-tier service to their customers, ensuring road safety remains a top priority.

This latest technical insight is part of Comline blog, which contains an archive of material that includes explanations of technical terms, best practice advice and product information. This platform is updated regularly, so why not check it out? Visit www.comline.uk.com

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