The main troubleshooting on CLI that you can use will be to do grep, then select which log you want to tail.
See this article for example http://tinyurl.com/6ekeec .
It will really depend on what is the problem with the wccp, the way how you will do troubleshooting.
I suggest going through kb article, and search for wccp, and they will likely give you information you will fnd helpful.
Otherwise, please give further information on your wccp problem, and maybe I can direct you further.
I hope this helps you.
Regards,
Eric