ballast fills without pump

[jasonwm]

my bags auto drain too when i add more weight (more sacks) on top of them for surfing. is there a way to close the drain valve so they don't leak out the drain line?

There is no drain valve in the stock system. You could install a ball valve after the drain pump that you could manually close, or you could upgrade your factory bag to a larger one and have it all controlled with the factory system.