View Full Version : MP40 Grinding/Thumping

01/04/2017, 08:06 AM
I have an MP40 with upgraded QD driver which was working great until a tank breakdown about a month ago. I went to use it last night and the unit is making a terrible grinding/thumping noise. After 30-60 seconds the noise gets worse and the wet side starts spinning in the tank. I can hear the motor ramping up/down even though the control is set to constant.

Looking for guidance on what parts to replace (driver, wet side, dry side) if possible to avoid replacing the entire unit.

01/04/2017, 08:17 AM
Pull apart the wet side per the maintenance instructions and clean/inspect it thoroughly. I suspect that there's just some dried up junk impeding the impeller, though a swollen magnet is possible.

01/29/2017, 04:49 PM
I have purchased a new wet side and I am still having issues.

Upon initial installation, the dry side was making a steady purring - not the normal operating noise, something a little louder with a steady thumping. I switched the control to constant (green) and turned up the flow - the pump ramped up, but after a few seconds turned itself down. The dial switched to yellow and the left and middle buttons as well as the dial became unresponsive. I could turn the unit on and off with the right button but it was still locked. I unplugged the unit and it reset. I switched back to green and turned the flow up - noise is actually sounding better now - but again, after about a minute the pump slows itself down, dial turns yellow and controls become unresponsive.