Guest zbrakes Posted April 12, 2008 Share Posted April 12, 2008 Here is the proper procedure for bedding in / burnishing new pads and rotors: Basic Initial Brake Bed-In For optimal use of any given brake system, the pads and rotor have to be compatible with each other. The bed-in procedure establishes that compatibility between the pad and rotor. This is achieved by a combination of rubbing speed, temperature, line pressure, and Inertia. Bed-in is also influenced by pad and rotor material chemistries. It is always recommended that only compatible pads and rotors be used in any given application. Bedding in advantages: 1. Gradually heat treats the rotor and eliminates any thermal shock in the rotor. 2. Burn off volatiles and moisture from the resin that is near pad surface. This will eliminate “green fade.†3. Establish a layer of transfer film about a few microns thick on the rotor surface. Shearing of the film during friction is an effective source of friction force. Otherwise, when using a freshly ground rotor without the transfer film, the main friction force would come from cutting, plowing, or scoring the asperities on the rotor surface. This leads to inconsistent braking effectiveness. 4. Mate the two surfaces to a near perfect geometrical match, so that the contact area is high, and therefore the friction force is increased. 5. The performance of a fresh rotor/fresh pad system would be inconsistent. This is due to ever-changing structures and properties of the two mating materials. Bed-in of pads and rotor will form a stable transfer film. 6. If bedding in procedure is not applied, a stable transfer film may not be established for a long time. In other words, the rotor surface would have to be constantly regenerating a film that is not quite stable for a long time. This effect would reduce the performance and increase the wear. Basic Bed-In Procedure Always consider the Brake pad manufacturers bedding in recommendations. 1. After installing new disc rotors &/or brake pads, perform 8 to 10 slow downs applying moderate pressure from approximately 50 – 60 kph without coming to a stop. 2. Make an additional 2 to 3 slow downs applying heavy pressure from approximately 60 - 70 kph without coming to a stop. 3. DO NOT DRAG BRAKES! 4. Allow at least 15 minutes for brake system to cool down. After step 4 your new disc rotors &/or pads are ready for normal use. Be aware that the full bedding in process can take up to 300 – 500 kms depending on driving style. During this period try and avoid any high speed hard braking to a dead stop. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted April 12, 2008 Share Posted April 12, 2008 I just want to add to step 4. Allow at least 15 minutes for brake system to cool down. While Driving Never stop, or park a car with hot brakes. Quote Link to comment Share on other sites More sharing options...
Gavin Posted April 12, 2008 Share Posted April 12, 2008 good info, thanks! Quote Link to comment Share on other sites More sharing options...
Calgary280ZT Posted April 12, 2008 Share Posted April 12, 2008 Timely stuff, I'm doing the front brakes for MSA and now I know the correct method for breaking them in. Thanks! Quote Link to comment Share on other sites More sharing options...
mario_82_ZXT Posted April 12, 2008 Share Posted April 12, 2008 I would contact your brake pad manufactures for bed in procedure. Though these are pretty generic, some brake pads require very specific procedures to burn in correctly. Mario Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted April 13, 2008 Share Posted April 13, 2008 This is where I got my comprehensive brake care/bedding knowledge: http://www.baer.com/technical/braking-202/index.php Quote Link to comment Share on other sites More sharing options...
Guest zbrakes Posted April 14, 2008 Share Posted April 14, 2008 The process does 3 important things Heat treats the rotor - (you should consider some moderate heat cycling prior to bedding to avoid thermal shock - that is the bane of gray iron) Burns off excess bonding resins Produces a transfer layer on the rotor surface that allows the adherent friction chemical reaction to work optimally. Some notes Ceramic pads bed easily - they are soft crap - but also overheat easily and 'over-transfer' on the rotor - and you get the pulsing that makes you say..."My rotors are warped' (which they are likely not). I hate ceramic pads. Semi metalic street pads - like Hawk HPS/Porterfield R$-s etc - take a bit more work to bed - but usually give very smooth - although sometimes noisy brake operation. Quote Link to comment Share on other sites More sharing options...
Guest zbrakes Posted April 14, 2008 Share Posted April 14, 2008 I just want to add to step 4. Allow at least 15 minutes for brake system to cool down. While Driving Never stop, or park a car with hot brakes. That is correct - and VERY IMPORTANT Hot brakes at a stop are probably the biggest cause of PROBLEMS Treat rotors like an engine - slow warmup and cooldown - pays off. Quote Link to comment Share on other sites More sharing options...
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