Hi, after pressurising my windscreen washers to 40 psi I was impressed to see I had a nice set of roof washers. Then 2 or 3 days later just a mere blub blub. Im thinking it must be a tiny leak to still have some pressure left to blub a little. The cap looks alright but who knows. Was wondering where are the common spots for this system to fail? Where I'm at with things are it is 1 of 2 things left for a roadworthy. I would prefer not to put in an electric one as I think it's a cute feature, i like original things and all in all not that fussed if i have to squeegy it when needed. Thanks for any help.