Bobcat 331 excavator cylinder

Hello all- I have an older 90s model bobcat 331 excavator on a farm. I don’t use it very often, but it was operable last year. This year I noticed two holes approximately 5/8” diameter about 6 inches apart on the lifting arm cylinder. The middle cylinder of the three. When operating the excavator, hydraulic fluid is pouring out these holes. I tapped and plugged them, however one blew out while repositioning the unit. My question is what are these two holes for? And is this a type of relief mechanism that I need to loop together? Whatever piece/s were on there are now gone. I’m hoping someone can give me some insight on this. Thanks for your help in advance.