Coolant Level

[L76PWRD]

On my 2007 V-Max when I turn it on the coolant is at a good level, then I drive around running errands and I stop check the truck and it seems like the coolant level is almost empty. Then while the truck is standing the coolant level goes back to normal. Is this normal? Never noticed this in my older GMs.

[4wd]

Not normal I think

[SouthCo]

Doesn't sound normal but I've never checked my coolant while out riding around. If I go on a long trip I will check at every gas fill up along with the other fluids but so far my Sierra hasn't been that far from home.