The bottle had a 1mm hole so the pressure build up was minimal, and on taking the pump apart water had passed through into the motor. Don't think the p/p was new when I was given same. David, there is a picture of yours on the facebook site showing a replacement 'orange' pump, do you have a contact for this, and how has it performed over time? I'm happy to purchase a windscreen p/p via e-bay, but as I require it to pump each way, I am uncertain how you tell from the picture which are one way impellor p/ps and which are bi-directional gear p/ps. Any advice would be well received.