Why do O-rings fail?
O-rings and other seals leak for many reasons. A defective seal may cause some leaks. However, most leaks are associated with other factors such as installation method, gland design, and sealing environment. The Society of Automotive Engineers publishes Aerospace Information Report (AIR) 1707, Patterns of O-ring Failures. That report can often help a user to determine the cause of an O-ring failure.
