I'll ask again!

[LARRYEBOYER]

I posted a question down on the engine thread but I will post here if you all don't mind. I went flying today and when I landed I found coolant on the mast. I couldn't find where it come from so I lifted the pressure latch on the radiator cap. Coolant shot out of the top of the little cap on the top of the overflow bottle on the mast. This never happened all summer, why in the cold air of winter? I am hoping it is not a head gasket pressurizing the water system. Any ideas? would retorquing the heads be of benefit if head gasket?
Incidently, I have not added or deleted coolant since I put it in originally. :(
Couple other things: I checked oil and no water in oil. And when I landed, the water temp was normal. 185

[birdy]

Any time you open the cooling systm on a heated engine,even if it's not up to operating temp,it'll spit out some water coz it's under pressure.
If you were loosing compression through a head gasket,there will be some air under the radiator cap after it has cooled down if the overflow tank still has some coolant init.
If there is no air and the overflow tank is still full,you don't have a compression leak.

"This never happened all summer, why in the cold air of winter? "

Sounds like you ether overfilled it or you got a compression leak.I'd check for air under the cap.

[donshoebridge]

Larry,

Are you waiting for the engine to come up to operating temp before you make your takeoff run?

[Harry_S.]

I'm no mechanic Larry...but...when I built my RAF and flew it initially, I would have coolant exit the small hole in the cap of the surge tank, like as you have experienced. This was during warm weather. I had coolant in the surge tank as directed by RAF.

After I got tired of cleaning the machine off every time I flew...I emptied the surge tank and haven't had a problem since. On preflight, I remove the rad cap and check that the fluid is up to the top. On landing, there is coolant filling the line going to the tank and when the engine is cool the coolant has drained back to the engine.

Hope this helps you.


Cheers :)

[LARRYEBOYER]

Thanks for the advice. It just seemed funny that in the hot weather, no coolant questions. Now I fly in 24 degrees and I get a problem. I think I will also get a new RAD cap and try.

[StanFoster]

Harry: I might add a little to what you saidl. I keep just enough coolant above full so that I can just glance at my clear line going up to the overflow tank on preflight ....just to see there is water in it without taking the cap off. Of course its nice in flight to be able to glance out the back window occasionally to monitor that the water level is up to par.

Stan

[CLS447]

Steven, That's a good thought. It's possible.

Stan, When you said glance out the window to see if level is up to par. How are you telling this? Other than seeing fluid in the hose?

[Harry_S.]

Stan:

Good point...I shall add a cup of juice.


Cheers :)