Mitsubishi Electric Lancer Evolution-VII Workshop Manual page 1034

CLUTCH OVERHAUL -
Piston
Piston cup
Clutch Release Cylinder
REASSEMBLY SERVICE POINT
"AA PISTON/PISTON CUP INSTALLATION
After applying brake fluid on the inner surface of the release
cylinder and circumference of the piston and piston cup, insert
the piston and piston cup into the release cylinder.
Brake fluid
Specified fluid:
MITSUBISHI genuine brake fluid "DIA-QUEEN
BRAKE FLUID SUPER 4" or equivalent
INSEPCTION
RELEASE CYLINDER
(1) Check the inner surface of the release cylinder for rust
and damage.
(2) Using a cylinder gauge, measure the inner diameter of
the release cylinder at approx. three positions (deepest
section, middle, opening). If the clearance with the outer
diameter of the piston exceeds the limit value, replace
the release cylinder assembly.
Limit value: 0.15 mm
21B-7