My dad has a portable Whirlpool ac unit. for the last couple of days it stops running and needs to have water emptied. Can I fix this for him?

High humidity causes more water on cooling mode.

It probably has a tank that needs to be drained. Look for a drain plug.

My unit was working fine for a couple years but now it won't evaporate. It still cools fine but it also collects about 16 ounces of water every hour and then shuts itself off until I drain it. I'm wondering it the evaporative mechanism it broken some how.

this type of unit has a condensate drain bucket that holds the condensation that is removed from the air, this bucket needs to emptied when the light comes on.

I had the same issue of filling up after a couple hours but mine started making some pretty loud noises as well just before shutting itself down and lighting all three lights. The top drain valve would no longer work and the only way I could drain it was through the bottom (gravity) drain valve. I took the unit apart and found that the simple water pump that is used for draining and the evaporating process had lost the thin filter screen on the bottom and the screen became lodged in the impeller of the pump preventing it from spinning. I removed the worn and broken plastic screen, carefully pushed the impeller back up on the shaft until it bottomed out, and cleaned all the built up sediment off the entire pump. After reassembling everything, the ac unit runs like new again and the noise is completely gone. Cost? $0
I imagine you can just order a new pump from sharp and save the time and effort of cleaning the pump.
Hope this helps!

depending on where you live. do have high humidity. then you have excess amount of water that might make condensate. like very cold can of can of coke.

Air conditioners cause the moisture in the air to condense on the evaporator coil. The water that is created needs to have somewhere to drain. If the unit is in a humid environment, it will create allot of condensation. This kind of operation is not uncommon.

Your float switch is faulty, replace.

Check to see if the drain is blocked by particles/debris of any type. Also make sure that the unit is level--as level as possible. I have my Whirlpool Portable AC in 4 inch bed risers so I can drain it really easily. I slip under a small low rise pan and drain it every two days or so when it is running. Mine leaked when I tried to incline it backwards to make it drain faster. As soon as I leveled the unit the leak stopped and water again came out the hose. These units must be kept level to prevent leaks so now I always do that.

Sounds like the drain line is blocked you would have to take this unit apart in order to check this. I would use a can of air to blow out the leakage. Also make sure the unit is level