Replication with fail over cluster in SQL Server 2014
Yes you can upgrade without affecting current features .


To upgrade a SQL Server failover cluster to SQL Server 2014, you must run setup with upgrade action on each failover cluster node, one at a time, starting with the passive nodes. As you upgrade each node, it is left out of the possible owners of the failover cluster. If there is an unexpected failover, the upgraded nodes do not participate in the failover until cluster resource group ownership is moved to an upgraded node by SQL Server Setup.

MSDN