Kenworth T800 low coolant

I had to change my tank, float is a plastic covered magnet that floats up and down on a plastic tube in reservoir. Tank builds a little crap on it and it sticks float down when you hit a good bump. You can hit the top of tank with a rubber hammer ( gently) and it dislodged float.
Can also pull sensor out slowly and see if light goes out, this will tell if it is float sticking.

 

I recently had the same issue. Once in awhile, then constantly.
I have an ISX, 2 wire sensor plug. I am old school, simply unplugged it, no more issue. Watch the temp gauge just like always. Freeze, Nitrate & Molybdate test once in awhile and hammer down!

 

Pull test the wires about 1 to 2 inches from the back of the plug for the level sensor. Give them a good tug to be sure the copper is in tact. The copper wire breaks inside the insulation due to vibraton. This is very common on radiator mounted surge tanks.

 

If it's like my 2010 w900 it's a sensor that slides in the bottom or reservoir. They are bad to crap out. It's super easy to change as it doesn't go into the coolant. Bad part is it cost somewhere in the $150 range.

 

And that's why I'm old school, unplug it, watch the temp gauge as always.

 

I tried unplugging mine but started flashing engine warning lights when unplugged so had to get new sensor and plug her back up.

 

It's been a week, so far, no warnings.

 

Sweet! Mine is 09 with c15. Must be something in the programming on my truck. Done it many times on n14’s and 12.7’s to get um home with no problem.

 

How does watching the coolant temp gauge tell you what the coolant temp is if you haven't got any coolant?