Wireless backup for imac

Ok, here's the deal. I got a new imac education edition. I'm trying to setup time machine for backing up my new computer but I'd like it to be wireless. I have a 500 Gb Maxtor hard drive plugged in to my belkin router. I have a 3 year old imac that could hook up to my maxtor through the router no problem. I backed up the new imac once with time machine by hooking it directly to the maxtor but now I want to hook it up wirelessly and the new imac gives me a "connection failed" message every time I try. I want the best of both worlds, I want my external hard drive to be network hard drive and a time machine back up for my new mac. Any suggestions would be great.

I doubt that's going to work. Time Machine is primarily compatible with directly-connected external drives (any brand) but not with most non-Apple third-party routers. I'd suggest you get a Time Capsule (a combo router and hard drive) from Apple if that's what you're trying to do.

Perhaps someone else has a way to make that work, but my understanding is that TM doesn't support USB-based non-NAS drives attached to most third-party routers.

There are hacks to make it work with some non-Apple NAS solutions. Unfortunately, Belkin, who does make great cables, isn't known for great networking gear. What model router is it?