88 through the slot 390 in the pump inlet conduit 88 as the fluid level within the reservoir 54 is for instance at or near a full level the fluid pressure formed by gravitational force or potential energy has a tendency to force the fluid upwards and out of the fluid access valve 362 whenever fluid access valve 362 is in an open position through contact with tip 388 of pump inlet conduit 88 accordingly when the reservoir 54 is at or near a full fluid level and the tip 388 of the pump inlet conduit 88 contacts and depresses the ball spring 376 378 of the fluid access valve 362 fluid flows upwardly into the inlet port 222 of the pump body 200 and primes the pump body 200 with fluid because the level of the fluid in the reservoir 54 is higher than the level of the inlet port 222 of the pump 86 this self priming effect occurs without reliance on the operation of the pump 86 when the user activates the oral irrigator 50 and the motor 82 activates the pump 86 to cycle between its suction and exhaust strokes fluid is delivered to the tip 56 quickly and rapidly.