Mitsubishi 1989-1993 GALANT Service Manual page 1227

SERVICE BRAKES
SERVICE POINTS OF DISASSEMBLY
When disassembling the front disc brakes;disassemble both
sides (left and right) as a set.
6. REMOVAL OF BOOT RING
Remove boot ring with (-) screwdriver
7. REMOVAL OF PISTON BOOT/8. PISTON
Blow compressed air through brake hose to remove piston
boot and piston.
Caution
Blow air gradually to remove the pistons while adjust-
ing with a plastic hammer, etc. so that the two pistons
come out equably together.
remove the other.
9. REMOVAL OF PISTON SEAL
Caution
Do not use (-) screwdriver or other tool to prevent
damage to inner cylinder.
(2) Clean piston surface and inner cylinder with trichloro-
ethylene, alcohol or specified brake fluid.
Specified brake fluid: Conforming to DOT3 or DOT4