coolant loss

[Mike D]

I am losing coolant and I can't figure out where it is going. While mowing yesterday for about two hours (c-3 mower) I noticed white smoke from overflow pipe on radiator. The coolant level was low about 2 quarts. I filled it up and it seemed Ok. I mowed some more today for about one hour and after mowing, I put about 1 quart or so in the radiator. What's causing this? Thanks,
Mike

[Cub-Bud]

The coolant is either going out on the ground or into your engine

Because the cub uses thermo-syphon instead of a water pump, the sytem will find the correct level/amount of coolant and expel the unwanted amount out the overflow tube on the radiator. Have you over-filled the system It only holds a little over 2 gallons.

If the coolant is in the engine, you could have a problem with the head gasket or something much more serious. Check you engine oil level.

[Carm]

had a similar problem with the C. Radiator was overfull. I leave about 2 inches or so below the spout in mine. Yours may run slightly lower or higher. Make sure none is in the oil. With that much loss, you would probably see it in the exaust I would think.

[Bigdog]

Mike, watch the level closely and use it for a while. If the level does not drop below the top of the tubes in the radiator, you should be OK. You may find that it will find the level where it is happy and it will run there. Inspect and blow out the cooling fins in the radiator so that it can operate at top efficiency and unless you have a problem such as mentioned by others, it will level out.

[John *.?-!.* cub owner]

Mike, the advice aobut coolant level is good, but the "white smoke" worries me. I've never seen one give any kind of vapor when it was overfull. I wonder if your radiator fins may have trash in them, or possibly the tubes plugged up with calcium to the point the cub is overheating. Another possibility is a blown head gasket, allowing combustion gas from the engine into the cooling system. A couple things to try. It might be a good idea to run a compression test, to see if one or two of the cylinders are low. Also might try filling the radiator to the point the coolant is in the neck and start the tractor. Watch for bubbles indicating leaking head gasket. Note, the cub won't run very long this way until it starts pushing the excess out the overflow.

[Mike D]

Thanks for the info from the experts. No sign of water in the oil, and the white smoke that I mentioned was coming out of the overflow pipe because the engine was hot due to low coolant. No sign of white smoke from the exhaust pipe. It seems as if my Cub pushes out coolant through the overflow pipe if the coolant level is above the tubes in the radiator. I had the radiator boiled out about two years ago at a radiator shop. I will check the fins to see if they are clogged up too.