2003 Ski-Doo ZX Series Factory Shop Manual, Page 88Get this manual
Subsection 04
Section 03 TROUBLESHOOTING (TRANSMISSION AND BRAKE SYSTEMS)
SYMPTOM CONDITION TESTINSPECTION
BRAKE SYSTEM IS NOISYNORMAL USE1Check brake pad thicknessaPads are worn outReplace2Check keykeywayaKeykeyway is worn outReplace parts