Chery A113 Maintenance Manual page 8

4.10 Remove the piston. Prepare one wood board to hold the piston
and place the wood board between the piston and the wall of the
brake calliper. Press out the piston with the compressed air carefully
through the connecting bore. Place the guard plate (such as hard
wood) at the notch of the brake calliper to protect the piston.
Notice: Do not hold the piston with fingers – danger of clamping!
The brake calliper piston is prohibited from removal at will and
should be removed/installed only by professionals or under the
guidance of the professionals.
4.11 Check the guide sleeve. The guide sleeve should move
smoothly and freely when pushed with hand. Replace the guide
sleeve in event of jamming or stiffness. Notice: Apply the
lubricating grease onto the guide sleeve during assembling.
4.12 Remove the seal ring carefully with the plastic needle, clean the
brake cylinder and components with alcohol and blow dry with
compressed air. Carefully check the surfaces of brake cylinder,
piston, and flange. It's prohibited to conduct the machining process
on the brake cylinder and piston.
4.3 Installation of brake branch pump: Apply one film of brake
cylinder cream onto the cylinder body, plunger, and seal sleeve.
Attach the seal ring onto the circular groove at the rear of the brake
cylinder. Attach the dustproof seal ring onto the front circular groove
and press it in completely.