The likely point for a leak is at the top of the suspension struts. Open the hood and you will see a little plastic tube attached to the top of the struts. This is the area where leaks usually occur. The rest of the circuit requires access from under the car.
listen carefully for a leak at the strut top.

Now another reason for the motor running is IF the sensors that detect ride height have been damaged/gone bad. These attach to the struts under the wings part way up the strut. Made of plastic they attach back to the sensor which is body mounted. Possible that debris has caused damage. Had your brakes/tyres replaced recently? If the sensor "thinks" the car is low they will send a signal to the pump to keep pumping. Does the ride height of the car look the correct height. Is one corner at an angle?

Stuart