What does the leak look like? Drops on the media or dripping/weeping from the heads when parked or in the cleaning position? 4 months old is way too new to be leaking. Do you print a lot of banner material?
Fuzz from the banner material can get stuck under the heads and the ink will wick down the hairs and drip down onto the media, especially when the head is changing direction.
Got a photo of the leaks or problems it is causing in the prints?
When cleaning the head of my 1624 I have noticed very small droplets on the printhead surface at times, but they do not seem to cause any print issues. My printer is about 5 years old and I replaced the head, dampers, and maintenance station this year.