I have seen this more than once. The bridge is toast. I have tried replacing the injector when this happens with no luck at all. The only fix was to replace the bridge. With that said, I would assume you have the coax on the outside properly sealed. Rain will get in the coax connections and cause you problems if you did not seal the coax terminations.
Is the Ethernet protocol down? If it is, check the RG6 F connectors for corrosion at the outdoor unit. Dirty or corroded connectors can cause the Ethernet protocol to down. The only way to fix this is to cut the old connectors off and install new ones. I've seen this on several occasions and have fixed the problem by replacing the connectors on the cable.
Have three AP1230 with damaged ethernet ports maybe because of some electric shock etc. We still use them as repeaters since the radios are still working. Maybe you can use your 1310 as a repeater (or non root bridge with clients) if you cant get it replaced.