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lobo69
Active Member
USA
40 Posts |
 Posted - 04/26/2010 : 06:03:37 AM
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| Anybody ever "adjust" a viscous fan to come on sooner? Got a 444e running up a mountain with stops and would like fan to engage more without going to expense of electric. |
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Fastback
Top Member
1500 Posts |
Posted - 04/26/2010 : 11:17:03 AM
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quote:
Originally posted by lobo69
Anybody ever "adjust" a viscous fan to come on sooner? Got a 444e running up a mountain with stops and would like fan to engage more without going to expense of electric.
In my experiance the symtom of engine running hot and the viscous fan not coming on or often enough on a T444E is the result of a radiator that has lost effiency in giving off the heat needed to turn the fan on.
Cleaning or replacing the radiator should bring it back to near "as new" operation or you can also switch out viscous clutch for Horton EC-450 electromagnetic clutches that run off a sensor in the cooling system, those will come on and cool engine. |
Why yes, the ORIGinal CHARGER is a Fastback |
Edited by - Fastback on 04/26/2010 11:17:51 AM |
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mastertech
Advanced Member
274 Posts |
Posted - 04/27/2010 : 7:30:38 PM
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| In my experience the viscous fans on 444e have about a 90percent failure rate. Installing new ones just gets you a few months to a year. Just get a horton fan drive with kysor switch and problems will go away. Thermostats on 444e also have a tendency to fail closed or dont open up all the way. In an emergency you can open the coolant valves and crank up the heaters to limp the bus a ways if need be. |
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Bassman
Top Member
USA
558 Posts |
Posted - 04/28/2010 : 03:46:29 AM
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| We have had some problems with radiators plugging - especially the ones that are split between radiator and intercooler. If the radiator is not transfering enough heat to the front of the fan, it won't come on soon enough. I also had a DT466 that had an imbalance between the temp light and the fan clutch. I spoke with my IH parts guy and he looked it up on a chart and sold me one that kicked in slightly cooler and I never had another problem with the light on that bus again. |
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JustinB
Advanced Member
United States
490 Posts |
Posted - 04/28/2010 : 05:20:04 AM
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| Looks like after the cooling system is confirmed as good or bad, the next step is to change the system over to an electromagnetic or air (if you have air pressure on the bus). This confirms that the best adjustment for a viscous fan clutch remains a 13# post maul. |
I may not know the answer but I can usually find who does. |
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mastertech
Advanced Member
274 Posts |
Posted - 04/28/2010 : 4:13:02 PM
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quote:
Originally posted by Bassman
We have had some problems with radiators plugging - especially the ones that are split between radiator and intercooler. If the radiator is not transfering enough heat to the front of the fan, it won't come on soon enough. I also had a DT466 that had an imbalance between the temp light and the fan clutch. I spoke with my IH parts guy and he looked it up on a chart and sold me one that kicked in slightly cooler and I never had another problem with the light on that bus again.
It seems the ones with the botton style thermoswitch oin the fan drive seemd to raise in on temps as time went by .I suspect the metal in the button was hardening. I did weld a larger plate in front of the air cooler side to blend more radiator heat into the center switch to compensate. But in the end the viscous eventually failed. For the price of the vicous unit to replace it twice you could have had a electric drive purchased and no breakdowns. |
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Fastback
Top Member
1500 Posts |
Posted - 04/29/2010 : 08:42:13 AM
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We ended up replacing all our viscous fan clutches on the T444Es with Horton EC450s, through that process we had some near new takeoff viscous units. When I "adopted" a nearby districts buses I tried one of the near new viscous units on a problem bus, it worked no better than the old one. It was at this time I came to the conclusion that the "half" radiator and flat fan shroud was not the best combination with a fan clutch that depends on the radiator readily giving up its heat inorder to activate it.
Bottom line is IMO, the best fan clutch for this application is one that engages by sensing the coolant temperature in the engine and not by the temperature of the air passing through the radiator. |
Why yes, the ORIGinal CHARGER is a Fastback |
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Cal Mc
Advanced Member
303 Posts |
Posted - 04/29/2010 : 7:04:23 PM
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When installing an electromagnetic Horton fan clutch it will give you the option of installing a manual dash switch as well as the coolant temp sensor. Take advantage of that option, It will keep you operating should the coolant temp sensor fail. We also encourage the drivers to use the manual switch during engine cool down before shutting the engine off.
Another advantage to the Horton clutch is better warm-up during cold ambiet temperatures. Viscous clutches still drive until the fluid shears. It is amazing how much a diesel engine air cools! |
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mastertech
Advanced Member
274 Posts |
Posted - 04/30/2010 : 7:57:09 PM
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Dont forget to warn the driver that it will have a sudden loud engagement from the fan . Ive had a few call in paniced that there engine was blowing up.
On a horton you can also unplug the temp switch to get you home as it should turn the relay on when unplugged. Th kysor temp switches are very reliable but every couple of years I seen one go bad. You can also enable the ecm to engage the fan relay but the dealer will have to do enable it for you.
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"adjust" viscous fan ?
