Caching-Only Name Server down

[amran at isp.time.net.my]

Hi all

I'm deciding to add a Caching-Only Name Server. 
All the Primary and Secondary servers then will point to the Caching-Only
Name Server.
The purpose is to improve the resolving processes for the remote domains. 

Questions :
1) If the Caching-Only server down, what will happened to my Primary and
Secondary servers?
Are they still can do the resolving processes? Can all the DNS clients which
point to the these Primary/Secondary servers surf the Internet ?

Thanz in advance