I have 1997 Polaris 500 sportsman. Some of the time antifreeze will bubble back through the antifreeze holding tank on the side of the engine. What will cause this?

 

When does it do this? when its running for a few minutes or all the time?

 

When you shut it off and it sets for a while. I am going to replace both of the hoses from the radiator back to the block.

 

hey jonny let me know my 96 sp500 does the same thing...

 

The tank is an overflow. When the engine gets hot the antifreeze will expand and flow to the overflow. When it cools it will draw the coolant back into the rad. If your rad is a little low or has some air in it you may see some bubbles in the overflow. Take the rad cap off and make sure your coolant is all the way to the top of the rad.

 

thakns bro...i'll try that

 

What can we do to correct this problem? Mine just started this.

 

there is an air valve + a vacuum valve in the rad. cap. if its dirty or out of value it will be uneven when opening to dispence the expanded liquid into overflow.it won't be even,slow and smooth,you should barely if at all be able to notice it.it will be in surges.

 

I had this same issue on a 2000 500 and I did everything I could think of with no luck. Then Just blowing off changing the cap thinkin it could not cause this, I was wrong. I P/U a cap at napa I think it was a 13lb cap. I could see just looking at them this was it so after toped it off I ran it with the cap off untill all the air was out and put it on and all was good.