2016 M8000 LTD coolant system question

[snowrunner]

I'm trying to understand the coolant system a little more. Had my sled overheat on me and after doing a bunch of reading on here, think it might be the cap. I was low on coolant which explained the overheating. Filled it and watched it for awhile in the driveway. Noticed the overflow tube start dripping pretty good after being warmed up for a few minutes. The level was well below the hot line and nowhere near the cap. I was wondering what the black hose that comes from the top of the head to just below the overflow tube is for. Is it a return line and should it have coolant draining back into the tank. My thought is maybe the cap was loose and was causing a venturi effect pulling coolant from the black hose to the overflow. I bent the tabs on the cap and it seems tighter now. I haven't had a chance to start it up again and watch it. Just wanted to make sure there isn't something else going on. No smoke when running down the trail and the coolant seems to look good. Sorry for the long winded question.

Thanks.

 

[Big10inch]

Are you sure it wasn't low snow conditions and the 3 inch track that caused the elevated temp? You say "overheated" but please be more specific. Did your temp light come on? Did it go to the second level of warning? Was steam shooting out of the reservoir?


You probably just got it warm to the first warning level. This is getting pretty warm but not "overheated". It is warm enough to push some out of a full reservoir. The coolant loss may have been normal with the elevated temp and just topping it off is all you need.


It isn't a Polaris and you shouldn't have to worry about the temp much. Scratches down in low snow, let it cool if the temp light comes on.


The caps can leak, you probably have that fixed by bending the tabs a little. Sometimes cap wear out and will not hold the 15 lbs of pressure in the system anymore and puke coolant. That requires a new cap.


The small hose from the head is a pressure bleed. I do not think it normally flows all the time.


Doesn't sound to me like a big issue. I would top it up now and ride it.

 

[snowrunner]

Thanks for the reply. I was in about a foot or so of heavy wet snow. Scratchers down on the trail and in some of the off trail. Temp light was flashing and the digital gauge was flashing TEMP. I brought up the temp reading from sub menu (whatever it's called) and noticed it would start flashing about 182 deg or so. No steam or anything like that. Just kept an eye on everything until I go back to the trailer. I'm leaning toward the cap and low coolant. My concern was why it would drip in the driveway when I know the level is well below any overflow.

 

[mtncat600]

I have a new 2017 m8000 sno pro puking coolant out overflow
hose, no temp light seen, good snow bought a stant cap
from auto parts store leak stopped, then i bought a new
arctic cat cap leak came back , im unsure what im going
to run on it havent had a true test on snow with the two
new caps .

 

[Big10inch]

The cap is definitely a possibility. I would also make sure the only drip is from the overflow and not one of the many hose down at belly pan level, or a damaged cooler.


You may want to lift the front end some, run it to temp with the cap off and watch for air coming out of the system while topping it off.


Pressure check for leaks would be nice too, you would need a tester that fit the small cap.

 

[snowrunner]

Thanks. I finally got around to checking out. Ran it with the cap off up to temp and no drips at all. Ran it with the cap on and made sure it was on good and no drips. The only drip I had before was from the overflow and I had pulled the tube out so I could watch it. Everything else was dry. The only thing I did notice was the black tube below the overflow with the cap off once at temp would start spitting coolant back into tank. I hope and assume that's normal. Hope to get out this weekend and see how it is.

 

[jeffster]

FWIW, I have 2 15 M8000s, a 15 M6000 and a 16 M6000, and they I have managed to overheat them all, even with scratchers down. They don't love slow technical tree navigation unless it is deep powder. Just not enough track rotation to throw enough snow on the exchanger. So it is either turn them off and let them cool, or hopefully find a small open area to gas the heck out of it to get the track spinning. 10-20 seconds of that and temps will be fine again. The 16 is the worse as they implemented that surge function when it starts to overheat, and it is annoying as hell. Glad my wife rides that one as I would probably pitch it off a cliff.