viscous fan clutch troubleshooting

(The previous clutch had loose bearings.) 0000060428 00000 n It would definitely do damage. 0000069624 00000 n All rights reserved. A bum fan clutch drains horsepower from the engine to keep the mechanical fans running, which can ultimately lead to critical overheating, decreased fuel economy, and poor general performance. When I say it disengages, I mean it coasts to a stop! The sensor returns a signal pulse through the cooling fan speed signal circuit. (The previous clutch had loose bearings.) From the exterior, a locked-in fan clutch will be hard to diagnose with just a visual check. They contain a drive and driven plate with annular grooves that fill with a thick viscous silicon fluid. These fans are needed at slow speeds, typically below 35 mph and at idle. In our 97-98 AmTran REs, the 444s run 210* all the time, sometimes a little less in the winter, in the summer, the fans are almost constant on, and if it's hot enough (85-90* outside) they'll hit 230* under load. The engine temp reads a little low all the time, about 2-3 notches below 210. It disengaged once at 206 degrees, another time at 217 degrees but sometimes it stays engaged. T444E overheat problems - School Bus Fleet Magazine Forums Even if I pull the relay or unplug the fan it still runs fast. Never attempt to inspect or handle any of the mechanical components in the engine compartment while the engine is running. Fan Clutch Symptoms of a Locked-in Fan Clutch. If fan speed is not detected a DTC will be set. These fans are more efficient than flex fans that are controlled by engine speed instead of temperature. 3000000/10000 0000070596 00000 n Clutch fan check - See if any visible damage on clutch fan, 3. When it happens its especially hard to take when you need your vehicle or application to finish a job. 0000060995 00000 n It is possible something like a plastic bag could have got wound up where the shaft goes in to the bearing. In most cases, fan blades are designed to flex up to. These elements are natural in the process of Writing in a foreign language. A slipping fan clutch can result in failed cooling, increased engine strain, and poor fuel efficiency, which is why its important to evaluate the condition your vehicles fan clutch if you suspect it might be wearing out. 0000060378 00000 n Hmmmmm.. that truck looks awfully familiar. the cooling fan using a Hall effect sensor, which reads a reluctor track inside the fan clutch. This means that the fan should power down at higher speeds because the rushing air is sufficient for cooling the engine. When the fan clutch engages, it spins up greatly, increasing air flow through the radiator and over the engine. You should feel some tugging from the fan trying to get it going again. Before you go looking for your fan clutch, make sure your vehicle is in park, with the engine off and the handbrake firmly engaged. Keep holding it while the engine gets hotter, As it gets hotter, you should start feeling some tugging from the fan trying to get it going. Success stories from users of variable-speed cooling solutions. PDF IK0900075 - Horton Stratis Fan Hub Diagnostics Page 1 of 6 6% Keep an eye out for any visible components that are bent, crooked, or missing. Check with diagnostic tool scanner - See if the readings reach the desired levels, 6. These fans are needed at slow speeds, typically below 35 mph and at idle. By . Read more! Quick tutorial on how to refill your viscous fan clutch with proper fluid and reseal the chamber. But in the late 1950s, viscous fan clutches began to appear. As you could imagine, trying to stop a locked fan with a rag would not be a pleasant experience. For a better experience, please enable JavaScript in your browser before proceeding. How to test the electro-viscous fan clutch | GMTNation PDF IK0900075 - Horton Stratis Fan Hub Diagnostics Page 1 of 13 Both parts tend to wear out at about the same time, so if one is giving you trouble, the other may not be far behind. You could also put 12v+ to the white wire at the clutch (or at the relay if you can figure out which terminal it is). These issues will draw the PCM's attention, and it will turn on the check engine light to warn you about them. 450 Our community has been around for many years and pride ourselves on offering unbiased, critical discussion among people of all different backgrounds. Viscous fan clutch is going to be the norm when more industrial engine uses ECM/ECU. The engine cooling fan, made of plastic or metal, isnt hard-connected to the fan pulley or water pump, but instead is soft-connected via the fan clutch. This fluid's flow is regulated by a bi-metallic spring that opens and closes a control valve. Resurrecting this old thread. Simply follow the steps below and you rill receive a replacement part number. 0000069649 00000 n Try it again but pull the fan relay. When I said DO NOT TEST, that's with the method described with the rag. 1988467. X {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/4\/42\/Test-a-Fan-Clutch-Step-1.jpg\/v4-460px-Test-a-Fan-Clutch-Step-1.jpg","bigUrl":"\/images\/thumb\/4\/42\/Test-a-Fan-Clutch-Step-1.jpg\/aid9382520-v4-728px-Test-a-Fan-Clutch-Step-1.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"

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