Years ago, you couldn’t visit a garage without seeing a tin of copper slip sat on the bench, complete with paint brush, explains Scott Irwin MIMI, head of technical training at TMD Friction.
However, as braking systems have become more sophisticated over time, the practice of using copper-based greases can be problematic for vehicles, particularly those that rely heavily on electronics.
An issue with copper-based lubricants is that they cannot withstand high temperatures. As the pads cannot move freely within the system, this can cause drag and premature wear as a result. Products, such as copper slip, can react with steel and aluminium, which would cause corrosion should the two metals meet.
If you’ve ever had to knock the wheel off from the hub and wonder why, corrosion due to a copper-based lubricant could be the reason.
Most friction product manufacturers will not recommend copper slip to use in the brake system. When carrying out the replacement of brakes, TMD Friction recommends Ceratec or Hydratec.
The pros of using Ceratec when fitting brake pads:
It can withstand high temperatures – this is one of the main differences to copper-based lubricants. Unlike other brake greases on the market, because it works at high temperatures, this allows the braking system to work efficiently, which in turn means that the pads can move freely, eliminating drag and premature wear. Ceratec’s non-conductive nature means it will not interfere with the vehicle’s electronics.
It’s also easy to use – one tube of Ceratec can lubricate up to 35 sets of pads, as well as protecting against scratching and reducing corrosion within the braking system.
The pros of using Hydratec on the caliper sliders:
While using EPDM rubber has its advantages from a longevity and quality perspective, over time, should the material encounter mineral oil, the rubber will begin to swell. As these rubbers are now used more regularly within braking systems, and a selection of popular lubricants are mineral based, this causes a real issue for mechanics who need to be fully aware of the implications to ensure they’re not causing damage to their customers’ vehicles.
Looking at the actual impact of swelling rubber within a braking system, it is easy to see why mineral-based oils should be avoided. For example, rubber brake seals work by maintaining pressure on the fluids within the brakes themselves, making the seals imperative to ensuring driver safety.
If these seals fail, brake fluid could leak into the system and compromise the pressure capacity of the brakes – significantly decreasing the ability to stop the car. The seals also prevent any potential pollutants entering the system because if brake fluid becomes contaminated, it is extremely dangerous, lowering the boiling temperature of the fluid and the reaction of the vehicle when the brakes are applied.
With this in mind, brake seals are critical components that are found in various areas of a vehicle – brake calipers, master cylinders and brake vacuum boosters – emphasising the point of how important it is to ensure these parts are not compromised. Due to their functionality, all seals are manufactured using specific materials that can resist brake fluids such as DOT 3, DOT 4LV, DOT 5 and DOT 5.1. However, they remain incompatible with mineral oil.
So, how can EPDM rubber seals be properly maintained? Utilising a lubricant on key locations, such as the cylinder running surfaces, pistons and sealing elements, can improve the integrity of the parts whilst protecting against corrosion. Using a paste can also facilitate the installation of hydraulic brake components, making it easier to work on this specific part of a vehicle.
It is undisputed that lubricants and pastes are necessary and key to maintaining a braking system, but often it will be a multipurpose grease that a mechanic reaches for. The problem is, a lot of multipurpose greasing products contain mineral oil, or an unspecified petroleum-based oil that negatively effects the integrity of the rubber, causing it to swell or crack over time.
There are several greases available that are often seen as a mechanic’s trustworthy sidekick, but as times change and vehicles develop, the braking systems become more advanced and require more specific products to ensure their longevity. Whereas a mechanic could rely on reaching for the trusty copper slip, they will now have to consider the metal content and how this affects run out, electronics, premature wear and more.
Similarly, within the clutch and brake system, a multipurpose water dispersant spray grease is often the go-to, but this may not be the more efficient or effective product when taking the ingredients into account.
Having recognised these issues, TMD Friction’s premium brake brand, Textar, developed Hydra Tec, a lubricant specifically designed for components within a brake and clutch system, which is ideal for lubricating cylinder working surfaces.
Hydra Tec is compatible with EPDM rubber and commercially available brake fluids. It also protects working surfaces and metallic components against corrosion, thanks to its water-repellent properties. When utilised correctly, the formula prevents brake seizure and keeps all elements protected and moving, which ultimately keeps the customers moving too.
With so many brake grease options available on the market, it can be a minefield for mechanics to understand what product is best for the jobs that come into their garage. That said, it is imperative that garage technicians take the time to research the best lubricants on the market.
Mineral oil substitutes can cause seals to misshape very easily, leading to a host of other issues within the braking system. This cannot be overlooked by mechanics who need to work with customer safety front of mind as, ultimately, a driver’s life is in their hands.