Why Copper Grease Should Not Be Used on Modern Vehicle Brakes
Copper grease was once commonly used around braking components, but it is not the best choice for many modern braking systems. Modern vehicles use a mixture of metals, electronic systems and materials that can be affected by conductive copper-based compounds.
This guide is based on technical information from Textar, manufacturer of Cera Tec ceramic brake lubricant.
What is copper grease?
Copper grease is an anti-seize compound containing fine copper particles suspended in a high-temperature grease base. It can help prevent threaded or mating surfaces from seizing when exposed to heat.
The problem is that copper is electrically conductive and can react with other metals used in modern braking systems, particularly aluminium, when moisture and road salt are present.
Why can copper grease cause problems?
When two dissimilar metals are in electrical contact and an electrolyte such as salty water is present, a process called galvanic corrosion can occur. One of the metals can corrode more quickly than it otherwise would.
This is particularly relevant around brakes and road wheels because the area is regularly exposed to water, salt, heat and road contamination.
What is galvanic corrosion?
Different metals have different electrical potentials. When two different metals are connected in the presence of an electrolyte, they can effectively form a small galvanic cell. The less noble metal becomes the anode and can corrode at an accelerated rate.
Cast iron and cast aluminium, both commonly used in braking components, have a relatively small potential difference. Copper and aluminium have a much larger difference, which can increase the risk of galvanic reaction where copper-based grease is introduced between them.
What should be used instead?
Where a brake lubricant is required, a suitable non-conductive ceramic brake lubricant is generally a better choice than copper grease on modern braking systems. Products such as Cera Tec are designed for brake applications and help avoid the electrical conductivity associated with copper-based compounds.
Important: lubricant should only be applied to the correct contact points and never to braking surfaces such as the brake disc or the friction material of the pads.
Our approach to brake fitting
When we replace brake pads or discs, we use products that are appropriate for the vehicle and braking system rather than automatically applying copper grease. This helps avoid unnecessary galvanic reaction and keeps the work suitable for modern components.
If you need brake pads, brake discs or both replaced in Norwich, we offer mobile fitting at suitable home and workplace locations.
Technical source: Textar Professional — “The use of copper grease on modern brakes”. Product suitability can vary by vehicle and component, so manufacturer instructions should always take priority.