Getting ready for a LONG trip from Ont to Vegas. I was checking fluid levels this Am after truck sat all night and saw that the coolant level was very low in the tank where it is marked FULL COOL.It's about 2 inches below the halfway point of the tank. Is this something to be concerned with? 390000 KM with no noticeable problems.Should I top it up?
http://i39.photobucket.com/albums/e181/OleTrout/IMG_99161.jpg

When was the last time you chked the coolant level. What does the oil look like? When the truck is at operating temperature & shut off over night is the top radiator hose pretty tight; hard to squeeze.

I started getting a message about the coolant level about halfway through the 4th summer with the truck. It looked about the same level as yours. I added some Prestone Dex-cool (non-diluted) and distilled water and brought the level back above the seam.

Even on the hottest days here, the truck has always stayed below 210.

When was the last time you chked the coolant level. What does the oil look like? When the truck is at operating temperature & shut off over night is the top radiator hose pretty tight; hard to squeeze.

Thanks for the reply Mike.

When was the last time you checked the coolant level.
I look at it periodically.This time it seems a bit lower than usual. Rad was flushed and DexCool put in back in Oct 07 at 283000 KM. Water pump replaced Mar 08 at 302000 KM

What does the oil look like?
Oil looks good.Changed every 5-8000 KM

When the truck is at operating temperature & shut off over night is the top radiator hose pretty tight; hard to squeeze
I've read many posts related to the upper rad hose and have also checked it periodically and it's always been normal-soft

Thanks billaustin.
Regarding your reply, my truck is the same. Even on the hottest days the temp gauge is always been below 210 and I have never had a low coolant light come on.

coolant expands when it is heated. In theory if there is ANY coolant in the expansion tank cold, there is enough for when it is hot. As it heats up more will fill the tank. the problem is if you run out (in the expansion tank), and air starts filling the top of the radiator, then you loose the cooling from that portion of the radiator.

OK guys THANKS. I'll just top it up when it's cold with a 50-50 mix of Dexcool.That sound like the right thing to do?

Keep good track of the number of miles & how hard the old Dmax is working. I can see where you can be low on coolant with a wtr pump change as these engines can be some what of a stinker to burp the air out of. The reason for close watch is I had the same problem, light coolant loss, & kept trying to find the primary leak & found a number of small ones. Passed pressure tests dye tests etc. Well we are talking about a number of months passing trying to find the main leak, then all hell broke loose & it cost me a new engine. My engine never ran over 210 either towing or empty. The oil turned to jello & they tell me it was do the the coolant leak & Dex Cool. I chked the oil every day & never did catch coolant in the oil. It all let go on one short trip approx. 275 miles. I have seen my share of engines with water & coolant in the oil & none of them ever turned to jello. I was going to run my own test on Delo 15-40 & Dex Cool to prove or disprove the jello thing. But have not had the time as yet but will one of these days. I have kept all the info for miles on oil change & amount of coolant added etc. This info is not ment to cause you concern, just some caution. Good Luck & let us know what the coolant use was, if any, on your trip.

Thanks Mike. I keep pretty good records so I'll keep an eye on things.:)