Dns cluster zone delete

Hello,
I have a Dns cluster configured and working fine, Now i delete a old server and add new server with new IP , all accounts are transfered successfully.
The problem that i have a onlydns server ( all my servers synchronize dns to this server), I delete the old server from the cluster, but the cluster ( onlydns zone ) stil respona to my request ( like dns zone of the old server are still reside in the dns only server).
How to delete totaly this server ?? i disable bind service, delete it from cluster, but when i check dns propagation of my accounts, i see that the old ip still respond,

Thank you .