I replaced my sink water pump back in the spring, and
haven't used it since. A few days ago I poured 4 litres of
RV anti freeze into the water tank to winterize the van. I
heard the pump running but I couldn't get anything from the
faucet.

Should 4L be enough that the pump should be able to pick it
up from the water tank or do I need more? Is there something
else I should be doing to prime the pump?

Thanks,
Chris