Bleeding the cooling system

IHMO,

I have come to find that it is a good idea to bleed your cooling system on a regular basis. It only takes a moment, and I have found that there is usually just a smidge of air under the bleed screw.

If you boil the bike over, you really need to bleed the system. You'll be amazed at how much air is under the screw after a boil over.

I noticed a month or so ago on next years Husky 250 there is a small bleed line attached right at the top of the impeller housing. I'm assuming this is to purge any air that ends up there, which I'm also assuming is the top of the system.

Since I am not losing any coolant I would imagine this air could be coming from some cavatation at the water pump, or maybe just a bit of film boiling in the head area.

What do you guys think?

Hi Jeffs,

First off don't attempt to bleed your system while the bike is hot. See the link below to thread about this subject and my response. I have an 01 501 and always used the procedure described in the link as it was in the video that I got with my bike. You could give the bleed screw a try and let us know how it works out. Looks like it's not going to be easy getting to it though.

So you have a catch tank under your seat, that's great. I'm assuming it has a hose to the bottom of the tank so that after a boil over when the bike cools it will pull the expelled coolant back into the radiator. As with an automobile, there needs to always be some coolant in the tank, usually there is a cold level mark that needs to maintained.

The only problem I can see is that the overflow spigot on our radiators is not sealed very well, and while it's good enough to direct steam and hot fluid to a desirable location via the overflow hose, it may not be sealed good enough to draw coolant back from your catch tank and may pull air instead.

The over flow fitting on the cap tower is some sort of a polymer type material that is pushed in, and by the way has caused it's share of overheating problems when it drifts in a bit and catches on the bottom sealing surface of the radiator cap preventing a good seal.

Anyway, I would think that gluing this polymer spigot with some sort of high heat epoxy would be a good idea to keep it sealed.

If I am not mistaken you are going to have a very tough time mounting the KTM fan on the back side of the radiator, as the stock HBG tank is too close to the radiator. However, if you have one of the Boss's 4 gallon tanks it won't be a problem.

Hey, if you take your wife riding often enough I bet you won't be having to wait very much in the near future!

Best of luck!!


http://www.husaberg.org/index.php?name= ... 6807#56807

wasted said:

Hi

Would someone please tell in detail how to bleed the cooling system? The bike is FS650c -06. Should the engine be running when bleeding?

Click to expand...

No, the motor should be off.

Place the bike on a center stand, with a cold engine.

Remove the radiator cap, and make sure there is coolant in the tank.

Open bleed screw on head a few turns until coolant starts flowing out.

When no more air, or coolant with air bubbles in it is coming out of the bleed screw, re tighten.

Set correct level of coolant in radiator, put on radiator cap.

Go riding.