Dosing Pump Squeal

[balloonpilot]

I've got the 4 pump dosing set connected to my Profilux, recently one of my pumps has started to squeal when pumping.

What can be done to stop the squealing?

 

[Spinny]

Is it the pump, or the motor? If your not sure, swap the pump assembly with on of the others. If it is the pump assembly, I would try cleaning it.