Master Cylinder: Inspection
WARNING: This page is about a different car, the 2005 Subaru Baja. However, it is still accessible from the selected car via links, so may be relevant.
If any damage, deformation, wear, swelling, rust or other faults are found on the cylinder, piston, push rod, fluid reservoir, return spring, gasket, cylinder boot and hose replace the faulty part.
Courtesy of SUBARU OF AMERICA, INC.