I had the same issue: apache and tomcat worked correctly respectively on ports 80 and 8080, but the redirection with mod_jk did not work.
I set JkLogLevel=debug instead of info in apache2.conf.
I obtained the following message in mod_jk.log:
"missing uri map for localhost.localdomain:/jsp-examples"
I corrected this when adding the following JkMount statement in Apache virtual hosts configuration file:
JkMount /jsp-examples/* worker1
I hope this can help.