Al-ko Caliper Slide Boot Kit to suit all Alko hydraulic calipers.
When installing pistons use generous amounts of hydraulic fluid as a lubricant. Gently twist your piston home to be sure you do not damage them during installation.
Great idea to replace your piston seals at this point. If your piston is worn, then it is likely your seal is also worn.
Worn seals are the primary reason why pistons fail. a slightly damaged seal has let water into the hydraulic chamber causing the piston to jam.
Do not use grease during installation.