Intermittent retraction failure interfering with specimen advance

Hi everyone,I am experiencing a technical issue with my microtome's retraction mechanism and would appreciate some troubleshooting advice.The Problem:The specimen retraction function is faulty and works only intermittently. Sometimes it retracts properly for a long period of time ( more than 10 minutes) allowing me to cut but other times it fails The retraction pilot light does not illuminate and the microtome does not advance when the handwheel is turned until, after several turns, it starts working again and cuts again. This malfunction directly interferes with the microtome's fine micrometer advance. The other functions of the microtome work perfectly. Has anyone dealt with this specific issue before?Thanks in advance for your help!

Equipment: Leica RM2145 microtome year1997