Karcher pressure washers don’t pump water pressure, they pump volume of water, the pressure is made by a very small sprung loaded hole that sprays the water at great pressure in the end of the hose lance wand ( attachment on the end of the hose assy ) .Karcher supply ever spare parts you can think of  they supply washers, karcher pressure washer hose in different lengths, split valves and even control heads, but the most common spares asked for are hose and the water nozzle wand lances, They wear and because they are the most used part they.