I am pretty sure you don't need this cap. This is an AC filter cap which always blows up after time. Does the PS work without it ? If so, I wouldn't worry about it or eventually, you will have the same problem.
It probably is a good thing to replace; things will work without it, but it's not just there for show. And, if nothing else, the detonations add some excitement to life... ;-) That said, I don't know what the original value is, I'm afraid
Now I'm talking about PSU's I replaced the Rifa's in 6+ years ago here, but I *think* the Rifa in my one was .01uf and I replaced it with a .015uf (As I didn't have a .01uf in stock at the time)