Running NW6.5 sp05 and BM 3.8 SP2

Our site recently had virus issues on several PC's on network.
Workstations are now clean, but 2 "Craig Johnson configured" cache volumes
are over 90% used, according to NRM health monitor.

The Cache1 volume is not accessible; Windows Explorer, C1, and NWAdmin all
hang when attempting to interrogate the vol.

The Cache2 volume is ok; 2 gig size / blksize 16kb / NW 5.0 DOS partition
but only about 100MB free space. (Able to look via above tools)

Also, within the last few hours logged the following error at hp Proliant
IML screen: " Fatal Exception (Number 14, Cause Abend: Page Fault Running
Process httpexpThread23 Code Executing in Module Filesys.NLM v5.14 at
offset +78C23h)" Don't know if this is related, but occurred while
trying to look at Cache1 vol.

Q: What other means can be used to wipe ot this vol and re-create?

Thanks for any help to be had! Rick B