Hi everyone i hope someone out there can help i have a 1985 Nissan Ud bus which has a truck chassis under it and i keep having to replace the seals on my leaky foot valve as i am lucky to get 10 Min's once its turned off and all my air is gone which is a pain as i have to build up the air before taking off again.So has anyone put filters either side of their foot valve to stop rust dirt entering as it cost's $80.00 each time for a foot valve rebuild kit .Photos would be great as i know my foot valve has steal air lines and could any filters do or is this pressure greater than i think.Sorry its just i love my home-built fully engineered motorhome but this one problem keeps happening almost twice yearly and sometimes more as even a small leak is a pain sitting there for 5 mins waiting for air to build up .Cheers Darryl