I got a Raven 5 section shut-off valve bank on my liquid fertilizer cart. The 0-rings are leaking between the plungers and the body on a couple of valves. They have square shoulder 0-rings. Local raven dealer sent up new o-rings and they are round. They don't seal at all. I have an extra 3 section valve and took it apart and it also has square shoulder orings. Valve parts book calls for round... Am I look at the wrong parts book or something? Where would I get these square orings? This isn't the big O-ring between each section.