How do you know when the tool needs to be serviced?

The 15 kN (MAP2L) and 19 kN (MAP2L19) Klauke tools have red LED lights on the back of the tool that will blink for 20 seconds after a crimp. The 19 kN tool has a screen on the tool which indicates the number of remaining crimps. Take the tool back to an authorized dealer to have the tool serviced.