Abstract: An adjustable pressure control device relies on the change of shape or position of a control hose portion responsive to internal pressure of fluid being transmitted therethrough to control the fluid pressure produced by a pump. One embodiment of the device utilizes a short piece of high pressure hose in the fluid line which is adjustably deformed. As pressure builds up in the hose, the hose tends to return to its original shape, thereby actuating a suitable control instrumentality for the pump, such as an electric switch which opens the circuit to an electric clutch or to an electric drive motor for the pump, thereby temporarily stopping the pumping action. Another embodiment, to accomplish the same function, relies on the change of the arcuate position of a control hose due to variations in fluid pressure therein.