Arrived and snaked customers kitchen drain to clear clog and installed new disposal. When the kitchen sinks backed up due to clog I saw water coming from behind cabinets on exterior wall which lead me to conclude there was a break in the drain somewhere. Opened wall behind dishwasher and under sink to expose drains. Saw there was a cracked abs 1.5” 90. Repaired leak and ran water several minutes and didn’t see any further leaks.