Coolant Expanding??

[Chevyho]

I find this weird, but i fill the coolant bottle to the fill cold line, went for a long ride, came back and coolant had come out the overflow tube... I filled it up again but a tad bit below the line... went for another ride came back and coolant bottle was full but not overflowing... what would cause this? The temps never went over 126, coolers were all warm so it is circulating... Could a faulty resevoir cap cause this?

 

[jskattum606]

Check the torque on all of your head bolts. Could be compression entering your coolant system. O rings could be bad also

 

[94fordguy]

I find this weird, but i fill the coolant bottle to the fill cold line, went for a long ride, came back and coolant had come out the overflow tube... I filled it up again but a tad bit below the line... went for another ride came back and coolant bottle was full but not overflowing... what would cause this? The temps never went over 126, coolers were all warm so it is circulating... Could a faulty resevoir cap cause this?

An important question to look at would be, does the coolant return to the exact same level after the sled has cooled overnight? Typically coolant will expand a little as it gets hot and a bad cap will make the situation worse. I wouldn't think it would expand a whole lot if your only getting to 126, but if your cap isnt holding full pressure, it will.

 

[paramuir]

what should the head be torqued to?? hmm wait is this for a 900 2005 50th?

 

[03RMK800]

I have been amazed at how the fluid level varies in my 03 800 when its right-- the bottle can be empty, let it sit for a while and its full. When it was actually losing coolant, I had the system pressurized for a full day with no change in pressure.
Any way, after I changed the coolant bottle (the neck and opening egg-shape out) and got a functioning cap, it was all good. Stant makes a cap that NAPA sells for less than Polaris. Wherever you get the cap, pressure test it, too. I have had bad new radiator caps in several applications.

 

[Chevyho]

I will start with a coolant res cap, I dont think it is compression because both cylinders are dead nuts on 135, and wouldnt the coolant have a film from oil and gas getting in? And coolant does return to same position after cooling down.

 

[rmkboxer]

look at the bottle and if it is egg shaped where the cap goes on replace it

 

[billy2guns]

what should the head be torqued to?? hmm wait is this for a 900 2005 50th?

Why do you ask if this is from a 2005 900? The reason I ask is cause it sound like the problen I am experiencing on my 05 900 Fusion. Do you know what causes this or have a fix?

 

[jskattum606]

what should the head be torqued to?? hmm wait is this for a 900 2005 50th?

23 FT/ lbs. For the 900 I think. But if the coolant returns to the original level, this is probably not the issue. Won't hurt to check though. Cap is a good thought also

 

[nmmiles]

Im confused on the purpose of the cap....?? The bottle has a vent hose in it so why is it the cap is so crucial? Sorry if this is a silly question.

-Nolan

 

[Chevyho]

Here is the way I understand the cap to work, please correct me if I am wrong. As the coolant expands from heating up, the cap will hold a certain pressure in the bottle, the coolant level will still rise slightly. The lower part of the cap is made to open at a certain pressure (13lbs on 900's I believe) and allow some coolant out the over flow tube relieving some pressure. A malfunctioning cap will not hold enough pressure in the bottle allowing the coolant to rise up more quickly and perhaps drain more out the overflow than need be.

The top of the bottle does not appear to be egg shaped, so hopefully the cap is all it is. Are these caps known to fail?

 

[94fordguy]

Here is the way I understand the cap to work, please correct me if I am wrong. As the coolant expands from heating up, the cap will hold a certain pressure in the bottle, the coolant level will still rise slightly. The lower part of the cap is made to open at a certain pressure (13lbs on 900's I believe) and allow some coolant out the over flow tube relieving some pressure. A malfunctioning cap will not hold enough pressure in the bottle allowing the coolant to rise up more quickly and perhaps drain more out the overflow than need be.

You got it!

The top of the bottle does not appear to be egg shaped, so hopefully the cap is all it is. Are these caps known to fail?

Not sure how prone they are to failure in the sled world, but it's not unheard of in he automotive world. would be a cheap fix if your worried about it.:beer;

 

[BIGGDAWG]

Not sure how prone they are to failure in the sled world, but it's not unheard of in he automotive world. would be a cheap fix if your worried about it.:beer;

i have to disagree with you, i am a mechanic by trade in i have seen many a cap go bad. most automotive caps are 15-16lbs. the pressure is also there to raise the boiling point of the antifreeze. not so critical in sleds but in automotive applications when engines run in the 200-210 degree area it is.

this sounds like a cap problem too me or filling too full of coolant. check the coolant cold, ride it and then check it the next day when it is cold again. if it is in the same place you are good to go.

 

[paramuir]

Why do you ask if this is from a 2005 900? The reason I ask is cause it sound like the problen I am experiencing on my 05 900 Fusion. Do you know what causes this or have a fix?

the reason i asked this is because i noticed some coolant on my engine sort of between the cylinders, so i am wanting to check the torque on my engine aswell not sure wahts causing it yet so want to check out anything

where is yours leaking or where are you seeing fluid?

 

[94fordguy]

i have to disagree with you, i am a mechanic by trade in i have seen many a cap go bad. most automotive caps are 15-16lbs. the pressure is also there to raise the boiling point of the antifreeze. not so critical in sleds but in automotive applications when engines run in the 200-210 degree area it is.

this sounds like a cap problem too me or filling too full of coolant. check the coolant cold, ride it and then check it the next day when it is cold again. if it is in the same place you are good to go.

No, I agree with you... I said "it's NOT unheard of for one to go bad..."...:beer;:beer;

 

[Chevyho]

Anyone know a part number for the resevoir cap from Napa? I didnt know they sold sled parts?

The time it did leak, there was coolant on top of the res bottle and just underneath of it. I noticed the lower rubber gasket on the cap was way off to the side, dont know if it was far enough to let pressure past though.