If you want to get o rings for the future I would recommend going to a hydraulic shop and getting a good quality set and most importantly oil resistant. Take your old ones or your spare set just incase they need to match them. My local Napa auto parts does hydraulic lines I’m not sure if thats a thing at all of them.OK so got the kits in. All basic o rings save one brass part, hoping that is not normally a wear part.
I thinking I can just order orings to match for the future but not sure how to size them? Micrometer? What dimensions am I looking for?