I had this issue of water/soap overflowing and leaking out of the dispenser. I traced the issue down to the liquid detergent cup. In this video I'm showing you how the siphoning mechanism broke. I got the replacement part from Amazon.

Here is the link http://a.co/0TF5fV7 The product name is "LG Electronics 3891ER2003A Washer Liquid Detergent Container Assembly, Light Blue"