Water pump won't pull Antifreeze from the jug.

I had the same issue. Replaced the pump. No joy. Works fine for water use. I ended up first draining the system by use of the low point drain (in my case the shower head on the ground), and then using a jump starter with an air pump to blow out all the lines. I give it 10 seconds to come up to pressure, then I open it quickly. I do it 3-5 times per line. Ended up being cheaper than pink pop. Still have to do the drains though.