A pulsing spray pattern is more than an annoyance—it’s a warning sign. When your Graco sprayer surges or delivers inconsistent pressure, the issue usually traces back to worn or obstructed internal components. 1. Worn Pump Packings As packings degrade, they allow internal pressure leakage around the piston rod. This causes rhythmic pressure drops, which show up as pulsing at the g... https://erepaircenter.com