Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Won't seal..... Leaks after pumping

I've owned a previous marinator [ProLock] but it cracked, so trying this manual one is a real trick.. No matter how well you 'align & secure' the top, once you stop pumping after 10+ times, you can hear the air escaping. Inspecting the seal on the cover and the 'release valve', they show no misalignment...Removing the pump or leaving it in place doesn't do anything. I'm ready to return it to Amazon.. [maybe I'm not holding my mouth just right :) ]