Last fall I 'seemed' to be down on coolant- about 2 quarts; topped it up and checked it a week later-showed perfect level.
A month later seemed a bit high but didn't think much of it (because it winter & I was towing); now 4 months later it was still looking high (top of the bottle-above the old max.))-I just took 1.5 quarts out & now it's at the (new) Max. mark!!!
I am confused as hell- obviously when it showed 'low' it was not; could there have been a 'bubble' in the system; could it have been temperature related- as it was much cooler out when I noticed it 'low' & now it's much warmer out.
Anyone experience this????
This was my first fall & winter & spring with this truck so I haven't got a comparable.
The reason I was watching it so closely was I had the head gaskets replaced in the summer. No signs of issues with about 2k of heavy towing before noticing the 'low' & the above scenario????

 

I experienced the same fluxiation of level for months following a system flush. Simplely by chance I left the degas cap off while engine high idled and I was checking things out under the hood. When I looked closly for flow in the degas to confirm coolant filter was flowing,there was air bubbles riseing. The cap remained off for several more minutes and although the bubbles never completly stopped,they decreased noticably. Only slight variations ever since (10 or 12 months). I'm thinking "degas" might be a misnomer. A coolant recovery bottle is not under pressure and does a great job purging air during heat and cool cycles. And of course we expect the level to rise while going from cool to operating temp. If the degas doesn't actualy de-gas, after a coolant change or repair requiring partial refill,maybe the engine should have a long high idle with open bottle while toppong off. When I refilled I just dumped in 3 gallons of Gold and brought it up to max with dist water while idleing,caped it,closed the hood, checked and topped off first couple of times after it sat overnight. Here's something to think about. The main reason I have been given to use Gold is because it supposedly prevents tiny air bubbles clinging to cylinder walls. If bubbles are that critical and you are driving around with a huge fart floating around the system who's to say it doesn't cause the same problem that other coolants are purported to cause? That's the best I can come up with until someone comes up with something better.

 

Good tip- I'll try it.
Can anyone explain what the 'degas bottle' does?

 

Or why it's not just a normal overflow bottle like on other (gas) vehicles.
Of course, there is no radiator cap on our 6.0 - so that would have
to be added.