14. HYDRAULIC BRAKE STRYKER 125/150 Push the piston oil seals inward to remove them. Clean each oil seal groove with brake fluid. Be careful not to damage the piston surface. Piston Oil Seals INSPECTION Check each piston for scratches or wear. Measure each piston O.D. with a micrometer gauge. Service Limit: 25.30mm replace if below Check each caliper and caliper cylinder for scratches or wear and measure the caliper cylinder I.D. Service Limit: 25.45mm replace if over 14-11