Do we need to reboot cluster for SSL certificate

We have two cases regarding installing/renewing SSL certificate on our CB clusters.

Case-1: We have a CB cluster running with a SSL certificate and that certificate is expiring, so, we have to renew.
Case-2: We have another CB cluster which is running without any SSL certificate, and now our security team wants us to install SSL cert there. This cluster is already in use by real users.

Appreciate if someone can tell if we have to reboot the entire cluster for both the cases?