Coolant Reservoir

Found my coolant reservoir empty this morning after work. The truck came back from the shop last week and I topped off my coolant reservoir a couple days ago.
2008 V6 DCSB
No visible leaks, no residue in the engine compartment (shop detailed the engine too), water pump is dry and no residue, truck shifts fine, also - I just had both head gaskets replaced so that’s ruled out.
Aside from getting a new cap I’ve read through the forum and most point to a head gasket.
Any other thoughts and what else I should check?

 

was the radiator full when you got the truck back from the shop? If not it might have just sucked the reservoir empty to fill it. Thats the best case.

 

I hadn’t thought about that. I’m sitting at work waiting for a parts store to open for more coolant

 

I agree....it may just be sucking the coolant back into the system. I would check the tank when the engine is completely cold and add until it gets to the full mark. You might have to do this 2-3 times...checking it when cold. Not unusual for shops to be in a hurry and not fully burp the system. Odds are it's nothing to worry about.

 

Thinking back, I haven’t driven very much since getting it back. It was more of a gut shot when I saw it empty after spending so much on repairs.

 

I'm not saying something isn't wrong. But my experience with countless coolant changes tells me that having to adjust the overflow tank level after the fact is certainly not unusual.

When I do a DAF on my Tacos system I often times have to add a bit a day or two later.

Since the temps are up you probably aren't using your heat. If you have time, run it in the driveway with the windows down heat turned on all the way. If the engine is cool, pull the radiator cap off as well. Let it idle for about a half an hour. This will help to purge air in the system.

Throw the cap back on, top off the overflow tank then just keep an eye on the level when the engine is cold and add if necessary. Eventually all that air will be replaced by coolant and you'll be good