The idea was that the fan was sucking air in through that gap in the sides instead of through the radiator. Yanmar published a service bulletin in the 1980's in which they suggested owners of some models with overheating problems add foam rubber weatherstripping between the fan shroud and the radiator. A clogged air filter will cause the tractor to work harder and possibly heat up faster. A hoses inner lining can separate causing a bubble which can block the water flow.Ĭheck your air filter. Remove them & be sure the inner lining of the hose is still intact. If the belt slips your fan & water pump wont spin fast enough.Ĭheck your hoses. The belt drives the water pump and the fan. You may need to replace it.īe sure that your belt is tight. It may not be possible to flush the radiator if the buildup is severe enough. This indicates that the coolant is not flowing through the radiator correctly. You can run your hand along the front side of the radiator & see if you can feel spots that are noticeably cooler than other spots. Your tractor has 30 years worth of buildup in the radiator and it is likely causing a coolant restriction. I didn't count them) of tiny passages inside the radiator and the water may not be making it through enough of those to actually cool efficiently. Keep in mind that just because you can put a hose in one end and the water shoots out the other does NOT mean that your radiator is working right. Check your local air conditioning supply shop.īe sure that the radiator is clean on the INSIDE (flushed out). They make a tiny comb to straighten the fins if you have some smashed spots. Also be sure that the outside fins are all open (not bent in or crushed) and the holes between the fins are all open & clear. Never use a pressure washer on a radiator. Even having a very small percentage of the radiator blocked can cause problems. If you have straw or tiny pieces of grass plugging up the fins then the air can not pull the heat out of the radiator and the engine will get hot. If the water is boiling out of the overflow bottle it is probably too hot or you have other issues.īe sure that your radiator is clean on the OUTSIDE. Once the tractor cools, the water should be pulled back into the engine automatically. It does this because the water is heating up and expanding - it needs somewhere to go. This does not necessarily mean that it is overheating. It is NORMAL for water to flow out of the radiator into the plastic bottle on the side. Otherwise you may need to replace your switch or look for other possible causes. If the thermometer shows around that temperature you will need to move to step 2. The light should come on around 220 degrees. Placed into the water in the overflow bottle will tell you the temperature of the water and rule out any electrical problems. A $5 thermometer can be purchased at any automotive store. When they get weak they come on too soon. Temperature switches (the thing that turns the warning light on and off) do get weak. Is the tractor really getting hot? The light is probably coming on but that may not mean that it is really getting hot. If you see continuous bubbles in the radiator when the tractor is running then you probably have a blown head gasket.
#YANMAR 3 CYLINDER DIESEL ENGINE MANUALS 3ESDL HOW TO#
How to test- Let your tractor cool down completely. A lot of "overheating" calls are actually "blown head gasket" calls. Don't forget to add more antifreeze in the winter to avoid freezing.Īre you SURE it is overheating? If all of your water is "boiling" out of the radiator it could be a blown head gasket! Before you assume that it is overheating - check the water temp with a thermometer or mechanical temp gauge to be sure it is really too hot. We get at least 2 or 3 of these calls per day! Dilute your mixture to 25% or less in the summer if your tractor does not have a water pump. Too much antifreeze will not circulate correctly and does not conduct heat as efficiently. They use the natural tendency of hot water to rise to circulate the water.
These models use a very effective ThermoSiphon system and do not have a water pump. If you have a YM135, YM155, YM165, YM1100, YM1300, YM1500, YM1600, or YM1700 be sure that you are using NO MORE than a % 25% antifreeze mixture in the summer (add more in the winter).