Master Cylinder Inspection (Visual Inspection)

• Remove the master cylinders (see Front/Rear Master Cylinder Removal).
• Disassemble the front and rear master cylinders (see Master Cylinder Rubber Parts Replacement in the Periodic Maintenance chapter).
• Check that there are no scratches, rust or pitting on the inner wall [A] of each master cylinder and on the outside of each piston [B].

If a master cylinder or piston shows any damage, replace them.

• Inspect the primary cup [C] and secondary cup [D].

If a cup is worn, damaged softened (rotted), or swollen, the piston assembly should be replaced to renew the cups.

If fluid leakage is noted at the brake lever, the piston assembly should be replaced to renew the cups.

• Check the dust covers [E] for damage.

If they are damaged, replace them.

• Check the piston return springs [F] for any damage.

If the springs are damaged, replace them.

• Check that relief port [G] and supply port [H] are not plugged.

If the relief port becomes plugged, the brake pads will drag on the disc. Blow the ports clean with compressed air.

Front Master Cylinder [I] Rear Master Cylinder [J]