Okay I'm confused
 

So the other day I had my water pump replaced. The guy at the shop told me to keep checking my water for a while, he told me it would be in the plastic container on the passenger side that says engine coolant only and it should be about half full... I look in there and there today and it's not even a quarter full. Anyways my question is, does water seriously go in there??? Or is he wrong and am I supposed to be putting coolant in there like I used to?

50/50 coolant

that white bottle is the expansion overflow bottle for the radiator..

It has a hot and cold marking on it - the fluid should be between the two marks...

You would normally fill the radiator through the radiator cap - but since he did the waterpump - one would assume he filled the radiator already...

Water, coolant doesnt really matter, he probably put coolant in the truck and is having you fill it up with water if it needs any.

I live in florida were it gets HOT, and every once in awhile if it needs coolant just fill it up with water, but if I drain the system i will put coolant in it and fill the rest with water.

Alright well I already have a few jugs of 50/50 coolant. There's a little bit of water in the white bottle, do I need to drain that before adding 50/50 or is it fine to just mix it?

just add to it - about half full on the bottle

yes water and coolant mix fine

engine coolant pushes in and out of the overflow tank in response to temperature and pressure. its normal for this to fluctuate some, that's why there are the hot and cold marks on the tank. its also normal for some trapped air to push out after a water pump replacement, and for the overflow level to drop some. however - it should stabilize after a few days. if it continuously needs coolant every week, then its an indication of a leak.

:icon_laugh:

check the timing cover gasket it it continues to keep going low.

EDIT: did they replace the bypass hose? if not maybe thats why they say to keep checking it because they used the old one, and the trucks are prone to leak there from my experiance with rams.