I found the right tool, unfortunately it rounded off the cap square without loosening it. My master is leaking apparently at the fittings , so I’ll probably just replace if I can find one. I can’t see a number on the in place master, just Wagner Lockheed on inner side. Can’t see outboard side of master. Would anyone know of a source for the master cylinder for a 3 ton 1950 GMC 453 truck.
