How do you change the oil in a pressure washer?

Most pressure washer pumps have an oil drain plug on the bottom side of the pump. Some have a plug at the back bottom side. Many residential, mostly vertical shaft types, do not have any oil plug. Some manufacturers have decided to declare their pumps to be oil maintenance-free...mostly because consumers changing oil on small direct drive pumps can offer more problems than cures. These pumps can be serviced but require that the the pump be disassembled. Many of these direct drive pumps use a special full synthetic 30w non-detergent oil. The conditions for oil in a direct drive pressure washer pump are some of the most severe any oil could be asked to endure.

The motor oil can most offer be changed by tilting the unit on it's side. Turn off the fuel feed if possible when doing this. Others require the removal of an oil plug at the bottom of the motor. Usually reversing a 3/8" drive extension and turning it with vise grips will do this.