• Hi everyone,

    As you all know, Coffee (Dean) passed away a couple of years ago. I am Dean's ex-wife's husband and happen to have spent my career in tech. Over the years, I occasionally helped Dean with various tech issues.

    When he passed, I worked with his kids to gather the necessary credentials to keep this site running. Since then (and for however long they worked with Coffee), Woodschick and Dirtdame have been maintaining the site and covering the costs. Without their hard work and financial support, CafeHusky would have been lost.

    Over the past couple of weeks, I’ve been working to migrate the site to a free cloud compute instance so that Woodschick and Dirtdame no longer have to fund it. At the same time, I’ve updated the site to a current version of XenForo (the discussion software it runs on). The previous version was outdated and no longer supported.

    Unfortunately, the new software version doesn’t support importing the old site’s styles, so for now, you’ll see the XenForo default style. This may change over time.

    Coffee didn’t document the work he did on the site, so I’ve been digging through the old setup to understand how everything was running. There may still be things I’ve missed. One known issue is that email functionality is not yet working on the new site, but I hope to resolve this over time.

    Thanks for your patience and support!

Coolant Expansion Chamber

Russ

Russ

Husqvarna
AA Class
Coolant was dribbling out of the expansion tank of my bike during a ride today. That's not happened before in more than 17,000kms of riding. The bike was serviced by the dealer last week. Have they simply overfilled it & the excess is meant to flow out here, or is it a leak?

I let the bike cool down, after which I checked the coolant level by removing the radiator cap, and it was full, so I suspect it was overfilled.

The expansion tank is item 2 in this photo.

Thanks for any advice.

Regards,
Russ

image.jpg
 
Good chance it was over filled.This would happen each time a dealer serviced mine.Usually leak out on the way home,then it was good after that.
 
Thanks Will, I suspect you're right. It just seems to be a rudimentary design for it to leak fluid over the cases. I washed it off when I got home, but wouldn't want to leave it on for an extended period.
 
I have actually been a victim of THIS EXACT PROBLEM ever since I bought the bike back in Oct.2010 from dealership, and HAVE YET TO FIND A PROPER SOLUTION!!! The FATAL FLAW here is that STUPID breather hole in the cap of the overflow bottle itself, it DOES NOT take much of a lean angle to cause coolant to start leaking out of it, and not much further to have it drain completely!!! So far I tried gluing that "floating plug" in the cap, but then worried of overheating and explosion due to no vent. The best solution that I have found is to just make sure your radiator is topped off and then keep literally an ounce or two in overflow, and I'm good, unless I'm riding through Mulholland from Risk Store to The Snake!! That's because I lean soooo much through there that I scrape my pegs every time!!
 
Your coolant level shouldn't be affected much by lean, since the level stays parallel to the bike, unless you're hanging way off...
It's more about evaporation from heat and sputtering when the radiator cap vents a bit.

Mine has been bone dry since about 3 months after I got the bike, nothing will stay in there. Never been a drop low in the radiator...
 
Another option is to use my XF coolant. It never boils, so you don't even need an expansion tank. Never has to be flushed, lasts the life of the bike.
 
Tinken, expansion is a property of any matter. When something heats up (whether it be solid, liquid or gas) it will expand.

You will still need an expansion chamber regardless at what boiling point the coolant mix is
 
maxyb said:
Tinken, expansion is a property of any matter. When something heats up (whether it be solid, liquid or gas) it will expand.

You will still need an expansion chamber regardless at what boiling point the coolant mix is
Click to expand...


Much less so, though, with a low vapor pressure fluid.
 
This can simply be overfilling the expansion tank.There should only be a small amount in it- if the system opens it has to have somewhere to go. Bikes without expansion tanks that open dump it on the ground- but then never draw any back in upon vacuum/ cooling. That's the benefit to an expansion tank.

But depending on conditions and adding to the issue- the radiator cap could be opening too soon too often. This is a wear item. Once it opens- it decreases pressure which at that moment lowers the boiling point of the fluid. (more likely to boil). Also, the expansion tank cap-should not be glued nor deformed or it will burst or leak respectively. Fluid with a higher boiling point whether due to its chemical property or because of the static pressure of the system decreases likelyhood of the system exchanging. The radiator cap should be replaced if it is exchanging seemingly unnecessarily or prematurely. The only gauge I have for that is- knowing the bike. But the cap "bar" (pressure) ranges 1.2-1.4 bar oem usually. A worn cap could be at 1.0 for example and open early- exchanging sooner and more often. Then guys say my bike boils all the time- when its not 'boiling' its just exchanging. No need to go to a extreem HIGH bar cap- just ensure yours is maintained.
 
RDTCU said:
Much less so, though, with a low vapor pressure fluid.
Click to expand...
Correct, XF has very low expansion and is normally contained inside the radiator itself, without the need of an expansion tank. XF maybe utilized in a zero pressure environment, a pressure cap is not necessary.
 
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