MAINTENANCE SCHEDULE MAINTENANCE MAINTENANCE INTERVAL FOR HYDRAULIC BREAKER 0. For machine equipped with a hydraulic breaker, the hydraulic oil deteriorates faster than for normal bucket digging operations, so set the maintenance intervals as follows. Replace hydraulic filter element On a new machine, replace the element after the first 100 to 150 hours, then carry out further replacement of the ele- ment according to the table on the right. Change oil in hydraulic tank Change the oil according to the table on the right. 4-14