Thanks for that David, Heath Robinson maybe, but any DIY FOC upgrade/mod gets the thumbs up from me. Just one question, does this help in winter when the problem I found was water frozen in the ends of the washer jets, even with antifreeze windscreen washer being used, since there will be no flow when the jets are blocked with ice?
If you remove the non return valve( a round black plastic component in the pipework) And use a 50% mix antifreeze, I've found that once the thermostat opens allowing warm water to the heat exchanger, the washers worked, even through last winter.