CNC mill coolant pump needs priming?

Last night the night shift ran our Doosan 400 and didn't check the coolant levels. They ended up running it dry. This morning we turned on the flood coolant and nothing was coming out. The through spindle coolant works but it is a separate pump.
We checked all the filters and when we took off the cover to the coolant tank and turned on the flood coolant we see the coolant in the tank moving around, so it's doing something.

We are thinking that perhaps the pump needs to be primed because air got in the system. But I find it hard to believe that they need to be primed. I looked in all of our manuals and scoured the web to no avail.

So do you guys know if these pumps do need to be primed? If so how do you do it?

Any suggestions as to what else could be causing the problem?

Depends upon the type of pump. Most of the ones you see now look like an oversize swamp cooler pump. They don 't need to be primed. The type that looks more like a swimming pool pump do need to be primed. Easiest way is to disconnect the outlet hose and pour some coolant into the opening with a Dixie cup.

Like Larry said...try to prime it, but if it doesn't work or needs to be primed again better order a new pump as the impeller is probably shot. Many of them now-a-days are rubber or plastic and running dry melted them. Also check for a stuck check valve in the intake line. If you buy a new pump rebuild that one and have a spare. Can you call the Doosan Rep and ask them? Rich

All my doosan lathes need to be primed. They even have a set screw near the discharge fitting to prime the pump.