It took me about 2-3 days last year to find leaks. It was the first year I used the Lunchbox pump.
Here's some things that helped me:
1. Install a quick connect ball valve on each line about 3-4 feet from where they enter the pump. This will let you isolate each line to check if they are leaking.
2. Check carefully where the tubing is touching a tree. This is where squires like to chew.
3. Check to make sure you haven't tapped any trees that are hollow or partially hollow (like I did!)
4. If you still can't find the leak, isolate one line at a time. Run the Lunchbox and walk the line starting at the Lunchbox and crimp the tubing between every tap as you walk with a pair of pliers or vise-grips. If the Lunchbox stops, there are no leaks between where you crimped the line and the Lunchbox. Keep walking and crimping. When you crimp the line and the Lunchbox keeps running, the leak is between where you are and where you last crimped.
Mark
Mason 2x4 w/raised flue pan, 240 gal. sap tank, 80 Reds on 5/16 tubing and Lunchbox releaser/pump, 20 sugars on buckets