Originally Posted by
cyccommute
You probably aren't leaking from the bottom but are leaking from the top. The most likely spot is the bag's "cap". Either it isn't on properly or an o-ring has deteriorated. Fill the bag, turn it upside down, and squeeze it a little. You'll see where the leak is coming from.
I've had many, many bag and never had one leak from anywhere but the cap. The edge seams are sealed very well and are almost never a problem.
You've apparently never had one fail where the hose is fitted over the stem at the base of the bladder. Got a lot of mileage out of a few bladders running around with the Marines - while not common, it can happen with high-mileage bladders.