hi all.. I'm new to this, joined in desperation to sort problem out hopefully! I have run a shurflo pump in my van for 4 years. just recently my pressure at brush has reduced dramatically. I have an electronic controller which I used to run on 3. now I need 4 or 5, and of course then my battery starts flashing 'L' on the controller. I'm wondering if I need a new battery or pump!? only other thing I've noticed browsing the forum, is maybe I have an air problem as sometimes the brush jets splutter and spit! I do occasionally remove the small filter ( on pump inlet side) and wipe it out as I get a film clog it up from the tank. HELP!!?