BRAKE BEDDING OVERVIEW
Bedding brakes on a car is a combination of two different processes rolled into one compromised process when performed on the street or track. There are fundamentally separate technical parameters for bedding brake pads and for bedding brake rotors. When performing the bedding (breaking in) of brake pads and rotors on the car, there are huge compromises technically as the requirements for proper break in of each component is different.
To achieve optimum brake performance and wear, it is important that both the brake pads and brake discs have their individual technical requirements met before use. Properly bedded brake pads and brake discs will perform and wear at optimum condition versus components that were broken in inconsistently.
Pre-bedding brake pads and discs on a brake dyno using a fixed computer controlled program will ensure consistent performance of the components right out of the box. Pre-bedded brake components saves our customers time and money by ensuring all the parts work correctly, with virtually zero technical issues (such as uneven pad transfer, or thermal shock cracking of discs).
ABOUT BEDDING BRAKE PADS
Different types of high performance friction materials (brake pads) require varying amounts of brake energy, temperature, or pressure for their friction characteristics to stabilize and work correctly. The various suppliers in the market also use vastly different types of resins, binders and other agents to bond and manufacture these modern friction materials. It is critical that these resins and bonding agents must stabilize and the fiction material brought up to a certain operating temperature or energy so the resulting friction coefficient is stable and easily repeatable by the driver.
When performing this process on a car with a driver (human variable) there can be huge inconsistencies as to how the bedding of brake pads is performed. If the pads did not meet the proper level of temperature or brake energy during the break in procedure, there is a significant risk of the pads not working their best. The downsides can be premature pad wear, disc wear, and not optimum performance (friction coefficient) out of the pads.
ABOUT BEDDING BRAKE DISCS
Brake discs have a slightly different set prerequisites which need to be met during the break-in/bedding process. It is important to deposit a consistent layer of the pad material's transfer film on the brake disk. It is critical that this is performed by slowly raising and cooling the brake disc to avoid thermal shock. It is very common for a brake disk to distort (crack) due to the temperature being raised and lowered too quickly.
The process of pre-bedding involves breaking in the brake pads or discs on a brake dyno using pre-set programs. There are specific computer controlled dyno programs (which control pressure, inertia and temperature) for each individual component to suit their needs. There are individual mounting plates and fixings which allow various brake discs to be broken in on the dyno so that there is no risk of incorrect bedding. The brake pads and brake discs will be ready to use (Race Ready) once they come off the dyno. Not all friction materials are compatible with one other so the brake discs are usually bedded with the materials which are compatible with a wide range of pad compounds.
Step 1 – Adjusting the surface geometry of the brake pad and discs so there is consistent and even friction material contact.
Step 2 – Slowly building temperature into the brake pads or brake discs using a computer controlled program to avoid thermal shock, uneven pad transfer, cracking or distortion.
Step 3 – The components are subsequently run through a series of higher temperature brake events to stabilize the friction material to its optimum performance (bite) and ensure repeatability (stability).
Step 4 – Cooling down of the brake pads and brake discs.
Literature Credit: "Friction Specialist"