Webasco Anit-Freeze Odor

[truk4u]

I get an anti-freeze odor in the bedroom when running the Webasco. I took everything apart under the bed to access the heat exchanger and all is dry and no leaks. The Webasco is located under the bed in the last compartment on the drivers side. There is also an anti-freeze odor in the compartment and again, no leaks.

Jim Keller had a similar problem and had to have some sort of vent replaced in the compartment. All I can find is the following vent looking bronze part with a small screw on cap on top. The small little cap about the size of a valve stem cap, has a little notch built in the side. Could this be another bleeder and how could it produce anti-freeze odors without leaking fluid?


2353

[JIM CHALOUPKA]

Tom, that little brass cylinder, seems to be like what there is on a house hot water heating system. It is an air purger of sorts. You loosen the little cap on the top, and let out any air from the system. You then close the cap, but just snug it down. NOT REAL TIGHT. The entire gizmo needs to be replaced at times. When???? Contact Wrongagain on that.

It doesn't take much antifreeze on a hot pipe to give off the telltale odor.

Look for dried on leakage, often green in color.

Wrest assured that if it smells, it is leaking somewhere.

Is there any way you can pressure test the system.

[Jerry Winchester]

Oh boy.

Mike,

I can't wait to see how he blames us for this one. Weren't we going to save the "Anti Freeze Smell Spray" for POG V?

It seems to be missing from the "Get Even with the Krakman" box.

JDUB

[Jon Wehrenberg]

Tom,

This is purely a guess, but it is based on what you have posted. I will assume that you have looked at every joint and fitting and there is no leakage.

First, there are bleeders on my system, but since our systems are closed loops and pressurized at times it is unlikely anything is vented to atmosphere.

But there is one place you cannot see, and when the Webasto is working it is going to push the odor of coolant and that is the heat exchanger. It is probable given your verification nothing else is leaking that you can have a minute leak that literally evaporates before it drips away from the heat exhanger. When you call for heat, the fan blows the odor around. It could be a leak that opens when the system is warm or it could leak all the time, but slight enough to not show anywhere.

[Jerry Winchester]

Jon,

Do you reckon a radiator pressure tester could put enough juice in the lines to find the leak without the heat? Or would you just end up blowing one of the hoses off up in the bowels of the coach and creating a mess?

I have to think if you can smell it then it almost has to be in the heat exchanger inside the coach.

[rfoster]

Could be a minute leak like Jon describes undetecable because it evaporates--Is it in a location that you could place a small cold piece of glass or sheet metal to see if you get any moisture condensing on the cold surface.?

I know in the old car business that if I smell it -there is a leak. A heater core will fog the windshield in a skinny minute with the windows up and on recirculate and have no evidence of leak in the vehicle.

Tom just add some stop leak it will be ok. I have some really good stuff. The only down side is You will need to trade it off after adding.:cool:

[MangoMike]

Trukman,

I've been thinking about this since your call yesterday. I would start the circulation pump and let it run without heat (Jon's comment about evaporation) to see if any leaks develop.


2364

M1 is the circulation pump.

Remove the smallest white connector on the end of the brain. Should only be two wires on connector A. This powers the circulation pump. Remember on the Webasto BROWN wires are always ground. Add the appropriate power (12v or 24v) for your system to the terminals on the white connector.

Make sure the system is turned off inside the bus at the thermostat. As long as there are no electric valves (for webasto heat) on the CC (marathon has some), the pump should start circulating cold coolant.

You might also want to pull the Webasto head and remove the Air Swirler inside the combustion chamber to see if there is any leakage from inside this chamber from the heat exchanger.

2365

[Jon Wehrenberg]

Wherever the odor of antifreeze is first detected is likely to be closest to the area of the leak.

I can't be specific about how to look at the heater core for Tom's installation but if no evidence of a leak is detected around that heat exchanger, then I still suspect strongly it is somewhere in the heat exchanger. A bright light, a mirror, or even removing it from its mounting (hoses still attached) so it can be closely examined might be what it takes.

As an alternative, now that the weather is warming, isolate it. I assume there are valves to shut off flow to and from the heat exchanger. drain the lines to it and literally remove it from the bus. If there is no more odor that's the culprit.

[truk4u]

Thanks for all the suggestions, no visable leak!

2375

[JIM KELLER]

Tom, I think it is the vent. You posted a picture of the correct part and I can see the antifreeze stain on the top of the can. They took this part off, cleaned it and put it back together. No more smell ! I think you should look at that part since it is right under our heads in the bedroom. A mist is all you need for the smell. While you are at it find out what exactly what the purpose is of that part.

[Jon Wehrenberg]

Looks like brass corrosion to me Jim.

[JIM CHALOUPKA]

Just go with the indications and buy a new one.

[JIM KELLER]

Looks like brass corrosion to me Jim.

Well then Jon, I think he should polish that brass part ! And, you are probably right but I think it is some type of a vent that has something to do with the Wabasto.

[BrianE]

Tom,

My guess is that Jim is right. Your photo shows a Maid-O-Mist steam vent that is probably at or near the high point in your system. I had one that was leaking for months before I found and replaced it. The leak was very small.

http://www.acehardwareoutlet.com/(ivkze145u4sp4z552kblng55)/productdetails.aspx?sku=4065926&source=GoogleBase

[truk4u]

Thanks Brian, you solved the mystery.:p

[JIM CHALOUPKA]

Grainger sells them too, a good one and a better one :rolleyes:

Some of them are cleanable and repairable to an extent. If you want to play around with it put a pipe plug into its installation hole so you don't have an open system if anything should go wrong, and you don't have a replacement available.

Your problem might be the little teflon type seal inside the small cap, but to get one you would probably have to make it.