Newbie question on oil level during pre-trip inspection

If it gets below the hash mark lines you need to add a gallon and recheck. If it's less then a gallon low I wouldn't be too concerned but if in doubt add a gallon. Better to have too much than too little. Overfilling isn't usually a big issue unless it's WAY over.

 

Anywhere between full and the add mark is ok.
Too low and the pump will start to suck air, too high and the oil might start to foam from contact with the crankshaft.

When it gets down to the add line add 1 gallon.

 

This is a big diesel we are talking about, so forget all about "quarts" until you are driving your POV again.

 

Don't run it below the add mark.

That's a gallon low... we buy it by the gallon.

If you dump a gallon in when it's a gallon low, you shouldn't overfill it. Usually it just blows out the blow-by tube.

 

You're supposed to check the oil levels? I just let it run until the PM gets done.

 

one gallon...