Chlorine Feeder pulls then stops pulling

[NParker]

Can somebody help me with this issue? I am using a stenner 85M2 pump to automatically feed chlorine into my pool. The motor and hose will turn but nothing will be pulled out of the chlorine barrels. We replaced the hose line inside the pump and then it started to work. The very next day it stopped pulling again. Any ideas on whats going on?

Picture of the feeder: http://www.lockewell.com/images/stenner/m-series.jpg

 

[Bama Rambler]

Are the rollers pressing hard against the pump tube? They should be spring loaded and if the springs are weakened it'll cause the peristaltic action not to work.