Garage Files: How To Regain That New Brake Feeling
can be pushed out too far. Three to five millimeters exposed should be perfect for most brakes. With the one piston now exposed, it’s time to clean the surfaces that seal the brake from brake dust, dirt, grime and debris.
8-With the inside and outside of the brake now clean, it’s time to lubricate the piston surface. With Shimano brakes, you should use Shimano-brand mineral oil. Just a couple of drops applied directly on the exposed piston is perfect. Never use any lubricant that’s not specified by the manufacturer for this. Shimano recommends using a few drops of their mineral oil, while other manufacturers recommend continuing to move the pistons and allowing the system to lubricate itself. Using lubricants other than those specified, such as chain lube or fork oil, will cause seal problems, pad contamination and a host of other problems.
9-Use the plastic tire lever to push the clean piston back into place. Sometimes, using the body of the caliper for leverage with the tire lever can be useful. Then, repeat with the opposite-side piston. Extract the piston using the tire lever and pumping process, then clean with a fresh isopropyl-soaked Q-tip.
10-Once cleaned and lubed, check to see that the pistons are extending equally by pumping the brakes one to two times without the pads, wheel or rotor in. If they look like this, with an equal amount of piston showing after a couple of pumps, you’re ready to re-assemble.