Remove squid cache manually

Stop squid using the command /etc/init.d/squid stop

Next Delete cache directory using rm -rf /var/spool/squid

Create new cache directory using mkdir /var/spool/squid

Change ownership to squid user chown squid:squid /var/spool/squid

Create cache again using the command squid -z

Finally start Squid using the command /etc/init.d/squid start