liquid cooled, too much antifreeze?

[Vic]

The Buddy is air cooled, but my Sym is liquid cooled and I have a problem that I need some advice about.

Riding home on Friday my scooter started to overheat, I made it home by keeping it very easy and called my mechanic. He looked up where to find the little window to check the coolant level and where to fill it and I looked at it while we were on the phone. The little window is completely white. I waited until the next morning to open the fill and looked inside and could not see any liquid. I got some 50/50 and poured it in, the window is totally white and useless, it is impossible to see any level through it. I put coolant in until I could see the level.

My question is this: If I have a little too much, meaning above the "max" fill line, is this dangerous? What would happen?

I have always taken my scoot to the same shop-my Sym dealer, and the fact that the mechanic had to look up where to look at the window tells me that all of the times it has been in for maintenance and checks, this has not been checked, so it could be that I have a fast leak (I should be able to determine this by going out today and looking inside the tank to see if there is fluid at a level I can see or not) or a slow leak that has been going on since I bought it (I park on a packed gravel pad that has some grass growing in it, so I likely would not notice anything on the ground) or it could have been underfilled for months. There is no way to tell at all.

Since this is something that I now know about, I will, obviously, be checking on it myself.

Thoughts?

Thanks,
-v

[Cheshire]

As far as antifreeze goes, what I know is from cars. Liquids (such as antifreeze and water) expand when heated. Most systems are designed to accommodate for a certain amount of expansion: overfilling will over pressurize once it's heated up. That's your classic movie scenario: steam blowing when you open the cap, etc.

You could stake down a piece of cardboard, a sheet of plastic, or the like under your scooter for a couple days/nights if you're trying to determine if you have dripping leak. That might work on a gravel/grass parking spot, yes?

[pocphil]

There are two different types of cooling systems used on modern liquid cooled scooters.

Why is this important?

Most engines run best at around 200~240 degrees, but water boils at 212. Coolant alone moves the boiling point from 212 to 223. Pressure is the second way that the boiling point is raised; most vehicles have between 13-15 psi in the cooling system. This raises the boiling point approximately 45 degrees. Now in theory we can run the vehicle to over 260 or 270 degrees without the coolant becoming vapor and escaping the cooling system.

The most common is a pressurized reservoir with the only pressurized cap being found on the reservoir where you fill the coolant. If your reservoir cap looks robust and has a valve up in the top of it. This is what you're working with. Usually there will be no cap whatsoever on your radiator, just supply lines coming in and out.

The less common is the non-pressurized reservoir system. On this system your reservoir cap will not have a pressure relief valve built in, but there will be a conventional looking radiator cap mounted to the actual radiator of your scooter. The reservoir will be covered with a simple rubber stopper or cap.

In the pressurized reservoir system (or what some people call the closed system) normal coolant expansion fills the reservoir. When you add too much fluid or the engine gets too hot the pressure rises, the valve opens and you lose a LOT of fluid in a hurry. This fluid goes out to the world and is not recovered. The valve doesn't know when to close to prevent losing too much coolant and usually only closes once the pressure goes down.

In the non-pressurized reservoir system the Radiator cap is mounted conventionally on top of the radiator if your vehicle becomes too hot and the pressure becomes too great inside the radiator (usually 12/15 psi is nominal) the valve opens in the radiator cap and the now expanded ethylene/Glycol/water mix will escape into the non-pressurized reservoir container. If your reservoir is overfilled to begin with you can lose coolant as it is overflowed.

Cooling systems of both types will need to be purged of air to prevent air pockets which will prevent the coolant from flowing correctly through the motor. Usually this is achieved via a bleeder valve or the removal of a "high side" hose or bolt within the pressurized system. Simply taking the cap off the radiator while running the motor is NOT enough.

Most scooter companies use the pressurized reservoir system, which means they have to use a robust plastic in the reservoir which can make it difficult to see how much coolant is present. To make matters worse there is also usually bodywork around the reservoir or it's tough to get to, offering only a small window in the bodywork or a vent for inspection. Use a really bright flashlight and shake the scooter a little to get a good visual on what your fluid level is.

Good quality coolants can last up to 5 years which is excellent, however most of the scooters we've seen and tested (especially those from China) have had barely a hint of Ethylene glycol or propylene glycol. This would also suggest they didn't have the required corrosion inhibitors to protect your very important cooling system... especially during winter storage. If you have any doubts about the quality of your coolant or efficiency of your cooling system, have it serviced by a competent mechanic. The only motor failures we have seen at our shop in modern liquid cooled scooters have been the result of a blocked or failed cooling system.

[Syd]

Vic,
If your RV is like my HD, it has a non-pressurized reservoir (on cars, we used to call them overflow bottles). An yes, the view window is (nearly) worthless. The HD's window needs to be in just the right light, and I sometimes need to shake the bike a bit to see the level. I use a flashlight to make it easier to see sometimes, too.

[Vic]

Wow, thanks Phil, that is awesome info.

Thanks, Cheshire, for answering my next question before I asked it.

I am going to get a flashlight and head out there after dark to see if maybe I can get an idea of the level. It is good to know that it is not just mine that is like that.

My suspicion is that maybe it was not ever filled properly or fully, or perhaps after winter storage (I do not have a garage and it spent the winter on my deck under a tarp) it might not have been properly checked.

The reason that I say this is that my dealer/mechanic had to look up and call me back to tell me where the window is and where to add more, he even commented that now we know what is under that funny little cover under the left side of the handlebars. I have never had anyone else look at my scooter or work on it.

I will keep a close eye on the coolant level and see if I can find any changes happening, I am going to try to get it in to have it checked as soon as possible, but they are so busy at my shop there is no telling when they can get it in. I am working on getting my Buddy down to someone else to have it looked at, at this point it is totally unreliable too.

I am cursed I guess.

-v

[Vic]

So I got up before dawn this morning, grabbed my flashlight and headed out in the drizzle to check the coolant level in my scooter.

I opened her up and stuck the light inside and looked at the little opaque window and could not see a color difference between the light and the green which is where the coolant would start.

I bumped the scooter to try to get the level to move, stuck the flashlight back in and watched carefully, no dice.

I pulled it off of the center stand (after a lot of grunting and effort) and then put it back on the center stand (more grunting and effort), stuck the flashlight back in and looked, nothing.

By this time I was really frustrated. Maybe my flashlight was not strong enough so I went inside to the basement and dug through the camping gear, found the Mag-light and headed back out, lots of candlepower this time!

Then it dawned on me to check to see that there might actually BE a coolant level to check.

Umm, nope, it was bone dry. I double checked by sticking a chopstick in there to see if there was any liquid at all. Nada.

So, now we know, I have a leak. Well, a leak or I am the victim of antifreeze theft.

The shop is picking it up on Wednesday. He had me take a look at the oil and it looked okay to me. I am hoping that it is something cheap and easy like a hose slipped off or sprung a leak and it will be back in good order again soon.

Thank goodness this did not happen on my ride to or from Scootergate! I really got lucky there.

-v

[Syd]

If it's been running well, it's probably just a loosened hoseclamp. I wouldn't worry about it much yet.

Nice you can get to the the fill/overflow bottle so easily. I have to pull the headlight/front plastic off.

[Vic]

If it's been running well, it's probably just a loosened hoseclamp. I wouldn't worry about it much yet.

Nice you can get to the the fill/overflow bottle so easily. I have to pull the headlight/front plastic off.

I so much hope that it is something really simple like that! I am trying to not get too worried about it. The fill is right under the left grip, really easy to get to. The (almost useless) window to determine the fluid level is right inside the glovebox, beside the battery.

I left a piece of cardboard out there under it all night long and it did not seem to have much fluid on it this morning-there was dew, but no puddles under the scooter. It is a pretty slow leak, the usual neighborhood cats are all around, so I don't think anyone has been drinking it (I filled it with water to try to prevent poisoning any of them with sweet antifreeze).

I did not get a chance to actually check the level this morning, I will check it this afternoon, that will give me an idea of how much is leaking in a 24 hour period.

The shop will come and get it tomorrow and then I will know the full story. I forgot to ask my dealer, does anyone think this is something that would be covered under a warranty?

-v, keeping my fingers crossed for a loose or damaged hose that is readily apparent and easy to fix!

[DutchIV]

I know that I had a small leak on my Piaggio BV 200 but it only occurred during really cold weather. I could see a little seepage on the garage floor.

I think one of the notorious Vespa OEM clamps was loose. My dealer said I could put another screw type clamp behind the original clamp to see if that stopped the leak.

Didn't get around to it before I sold the BV.