Trailer hub grease fitting clogged

[PAT92B]

I replaced my hubs on my boat trailer after I installed the hubs I pumped grease in each new hub one hub will not except any grease does anybody have any tips on how to fix this. I've seen a tool that pumps a light viscosity oil through the zerk fitting but I have not seen it used on a trailer hub. Thanks for any info

[fishinwrench]

Peck on it lightly with a hammer to dislodge the stuck ball, and if that doesn't work then zerk fittings are cheap.  Usually 5/16 or 8mm wrench/socket and just replace it.