Why is my handle trigger leaking

Spray guns or extension wands leak at the handle because the water inlet assembly—specifically the seal or internal parts—is failing. The easiest fix is to replace the entire inlet assembly.

3300 PSI Spray Gun Inlet Assembly: https://surfacemaxx.com/products/water-inlet-assembly-for-3300-psi-spray-gun

4500 PSI Spray Gun Inlet Assembly: https://surfacemaxx.com/products/water-inlet-assembly-with-tube-and-slide-nut-for-surfacemaxx-4500-psi-spray-guns

9-ft Extension Wand Inlet Assembly: https://surfacemaxx.com/products/water-inlet-for-surfacemaxx-9-ft-extension-wand