Official: Brake Pad Knock Back Thread

[Cris@JCG]

Let me see if I can help here..

1st I agree with Mark on the roller bearing, they are not the best for road racing.. tapper is the way to go..

2nd I would see about rotor run out on all 4 rotors, when setting up a car for racing I always have the rotors turned on a brake lathe.. when you have rotors that are assemble to hat, hub, & rotor you are going to have a stack up tolarance of pcs that have been machined probably flat & parallel within .002 to .004 & you added it up & you have an excessive amount of rotor run out which will knock back the pistons & have pulsation in your brake pedal.. run an indicator on the faces of your axles & hubs & see what your run out is..

3rd Caliper flexing on brackets.. The Wilwood parking brake assembly/caliper mount has some flex on it.. remove your pads & grab the caliper with your hands & you can move it.. For racing I make new brackets out of steel or aluminum with gussets machined into them to make them stiffer & it makes a difference on how the pedal feels & when you are going into corner.. look @ it this way.. large diameter rotors, hydraboost, high friction brake pads & racing .. got to have good stiff caliper mounts.. attached is a rear mounting caliper bracket I made for racing.. for asphalt racing steel brackets are welded on rear axle tubes & front brackets are welded on a fabricated spindle/upright also have floating rear ends with large bearings.. Take into consideration that in some forms of racing they want piston knock back to free up rotational weight.. can be done with o-rings in calipers instead of square cut rings