I have a Belt Driven 4 GPM / 4000 PSI General Pump. It’s been working great, but today the customer’s lawn service arrived as I was washing the driveway. The customer asked me to disconnect my hoses that were going across the yard so the lawn service guy could finish the cut. 5 minutes later I reconnected everything, but forgot to open the water valve to my pressure washer. I ran it for less than 30 seconds without water. The inlet hose went flat so I ran over to turn the water on and it seemed to be working well. However, when I switch to the low pressure tips the pressure washer surges rapidly. What do I need to check/repair?
You likely just got air in it.
Let it run the air out. I had that happen a few times. I even run it with just the ball valve and close it some to increase pressure, then open all the way and mess with the flow. It might be a waste of time but I feel like I’m doing something.
Yep. Air in system