Repair DC snowboard boots by first assessing the problem.
These boots have a pump system that is designed to lock you heal in place when pumped up. it is used in various DC snowboard boots. unfortunately the air bladder they use is prone to failure. You will know when they fail because you will be able to pump them up, but your heal will slide around, making the boots useless.
Start at the top and unsew the bladder by cutting the threads. fill yor bathtub with water and put the liner in it. pump it up while looking for air bubbles. they will come from the source of the leak. DO NOT PUT THE PUMP UNDER WATER if you do, when you pump it, water will get pumped into the bladder.
ok, so after you find the leak and patch it you must sew it up. i do not have pics of this process because it was a huge pain in the ass. buy some thread that is the same size as the stuff you took out. carefully sew it back together. i used a headlamp and a mirror at times because of the tight quarters sewing inside the liner. use the holes from the original manufacturing process as a guide, go slow, be patient, and you will be back in business. good luck! go boarding!