I dont think its the bottle itself that is leaking but either one of the hoses or the pump unit itself is just faulty now.
I have filled the bottle half way, blocked the hole at the bottom and blown into it with no water seepage at all.
I know it leaks from somwhere near the unit coz its always wet there.
Its just annoying, when i actually want to use the washer wipers sometimes theres no water in there!