Thanks for the info guys,
OK, I've looked more closely at my washers... It seems that the leak isn't coming from the bottle as I originally suspected but from the headlamp washers. Water is constantly bubbling up from the jets, running down and along the bottom edge of the bumper, then dripping off.
I've also noticed that if I park my car half on a curb/drive so the car is leaning over to one side slightly, it leaks out of the headlamp washer jet on that side. If I turn the car around and do the same, it leaks out of the opposite side!!
I belive that there is a "splitter" on the hose that runs from the headlamp washer pump to the headlamp washers that can fail (think I read it on another post somewhere). If I'm right, I've got to take the damn bumper off my car to get at it! So I had a plan...
Could I simply crimp the hose from the headlamp washer pump (therby stopping the flow of water from the bottle to the jets) and remove the fuse that controls the pump? Would this stop the leak? Obviously my headlamp washers won't work but hey, it'll do till I can sort it out properly!!
What I need to find out is:
A, Which of the pumps is the headlamp washer pump
B, What can I use to effectively crimp the hose without damaging it?