APU Coolant Leak Under Fan Belt?

I’ve had this APU coolant leak for some time. It leaks about a cup a day if I use the APU. I have not been able to exactly find it. I know it leaks under the fan belt, and it’s not a hose nor the mini radiator. What are the possibilities? Is there a water pump in the APU?

 

I finally took apart my APU yesterday. I think one of the seals wore out completely. Do you think is this? I also noticed there are three seals in total. I tried removing the biggest seal, but the bolts are stuck. I am hoping it’s not leaking through there and only from the bottom round part.

 

UPDATE——

The coolant leak was coming from the water pump through either the weep hole or worn seals. It was a bit of work to get it done, but it’s not difficult. If you buy the water pump, also buy the thermostat and the temp sensor. Both parts go in the water pump. You will probably be left with one large o-ring. I think it may be for other types of water pumps or if your water pump doesn’t use a thermostat.

While you’re at it, you can also replace the belt that goes on the water pump pulley, and if your coolant hoses are damaged, you can replace those too. Don’t throw away the old water pump until you have put the new one on. You will have to remove a few parts off the old water pump to then put on the new one.