Losing antifreeze

[Tally Ho]

I do have a water heater, but checked the hoses in the engine compartment (where the puddle was) and could not find any issues. But the hose clamps were loose.

So still hopeful that was the source of the problem. Will know soon.

Thanks for the suggestion.

Greg

 

[Tally Ho]

Just wanted to (finally) close the loop on my antifreeze leak. It may be hard to see in the first photo, but the bilge under the engine is DRY!

2 things were contributing to the loss of antifreeze in my Yanmar 2GM20F I think...
1) I did find many of the hose clamps were a bit loose, and I tightened everything I could put a screw driver on.

2) in photo 2, you can see the filler cap for the heat exchanger tank. There was some rust around the flange that has the filler nozzle, but I never really saw any antifreeze there. I finally pulled the flange, and the gasket was pretty much gone on the lower edge of the flange. I did not have a new gasket, but used some instant gasket (you can see the gray material around the flange).

That seemed to solve the problem. I filled and the expansion tank, and so far, no leaks! Have run the engine a little to get out for a sail, and feel pretty confident that I solved this nagging issue.

Thanks for all of the help and suggestions from the forum.

Greg

 

[mz4wheeler]

2 things were contributing to the loss of antifreeze in my Yanmar 2GM20F I think...

I'm thinking neither. Losing that amount of AF you would see a leaking hose. The rust around the filler is probably not it either, unless you've seen AF leaking. What is the actual temperature? You really need a laser temperature probe, similar to this ebay item:

http://www.ebay.com/itm/Nice-Non-Co...-Temperature-Thermometer-Gun-E0-/262393295204

My guess is it starts to leak under load. Aim the laser at the thermostat housing to measure.

 

[JamesG161]

I do a spring engine servicing which includes genset Yanmar engine too. Antifreeze cooling system too using
https://www.amazon.com/gp/product/B003V9L05G/ref=od_aui_detailpages00?ie=UTF8&psc=1

With this tester, you must give it TIME to allow pressure to stabilize.

If it never stabilizes, you can "cold pressurize" and perhaps find the leak. Remember your thermostat is not open when cold engine.

WITH CAUTION...
You can repeat the test with a "hot engine" shutdown.
Jim....

 

[Tally Ho]

I'm thinking neither. Losing that amount of AF you would see a leaking hose. The rust around the filler is probably not it either, unless you've seen AF leaking. What is the actual temperature? You really need a laser temperature probe, similar to this ebay item:

http://www.ebay.com/itm/Nice-Non-Co...-Temperature-Thermometer-Gun-E0-/262393295204

My guess is it starts to leak under load. Aim the laser at the thermostat housing to measure.

Thanks 4wheeler,

I do have an infrared thermometer and will check it. But I was losing antifreeze over the winter while on the hard. So I am encouraged thus far. But I will keep an eye on things.

Greg

 

[Tally Ho]

I do a spring engine servicing which includes genset Yanmar engine too. Antifreeze cooling system too using
https://www.amazon.com/gp/product/B003V9L05G/ref=od_aui_detailpages00?ie=UTF8&psc=1

With this tester, you must give it TIME to allow pressure to stabilize.

If it never stabilizes, you can "cold pressurize" and perhaps find the leak. Remember your thermostat is not open when cold engine.

WITH CAUTION...
You can repeat the test with a "hot engine" shutdown.
Jim....

Thanks Jim. That looks like a great little tester. If I find I am still leaking AF once things get "hot", I may invest in that.

Greg

 

[MitchM]

you can buy a STANT tester for about $30. on amazon. the 'B' cap fits right into the radiator on Yan mars. it allows you to pressurize the antifreeze fresh water system without running the engine to about 7.5 PSI by sticking the STANT cap in place of the radiator cap. then pump air in. any weak clamp, pinhole in a hose or fitting will start spilling fluid. i used the STANT to find pinhole leaks in a hose from engine block to hot water heater that was losing antifreeze in a very slow leak behind a bulkhead and dripping it into the bilge. i never would have found it otherwise...

by the way all yan arms are very sensitive to keeping the right amount of antifreeze in the overflow tank. and if you don't seal the top of the o/flo tank well, the antifreeze will e vqaporate and you may get the engine overheat alarm. the gasket on the overflow tank wears out after 10 years or so... not a bad idea to replace your radiator cap gasket after 10 years, either...

 

[Tally Ho]

Thanks Mitch. Sounds like some good advice. I have never checked the gasket in the radiator flow tank.

Appreciate all the help.

Greg