Hi JM,
Rafeeq's advice is sound. Set your LUA 2.x server to retain only the past 1 revision and have it purge Manage Updates and Distribution Centers daily. Do not manaully delete and files from the LUA server's directories!
If you are running out of space on the C drive of that server, ensure that you are only downloading contents that you need rather than the entire product family, move your Temp Downloads to a different volume, move Manage Updates to a different volume, and use a remote Distribution Center rather than the default clu-prod.
Hope this helps!
Mick