I recently purchased a 2019 land pride RCF3610 with no manual. The manual I found online says to remove bottom plug to check the oil fill level and add to if low. But at the bottom, it says quantity of oil equals filling to the upper rear port. It also says there is supposed to be a vented dipstick on the top, but there is only the breather plug when I remove the bottom plug oil comes out when I remove the plug above it, no oil so obviously it was filled to the top plug which should I fill to the upper side plug or the bottom side plug?