Regardless of which side I fuel my class A from I have issues with the vent. Diesel keeps backing up to the filler and I have to stop to allow fuel to go down or only put the nozzle slightly into the filler and fuel very slowly! Not fun if I have to fill a lot...again this happens on both sides. Info: the vent line hole is on top of the filler and I pushed a coat hanger down aways and it doesn?t seen clogged, at least from tha end. Hard to believe that this would be issue from left and right fillers.