Assume it is the same as the X5. If so, there is one reservoir, and two pumps mounted on the bottom of the reservoir. Same pumps, one for front and one for rear. You can get a leak where the pumps clip in to the reservoir, or from the pump itself. If a pump wasn't working, you tried to use it, and then it leaked, it sounds like the pump itself. If a pump isn't working, it is easy to replace. You can test if it is the pump or not by swapping the wires on the pumps, and see if it works then. That will help isolate if it is the switch, the pump, or the plumbing from the pump to the nozzle.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue