Read about the Great Fleets Across America
Subscribe

School Bus Fleet Magazine Forums
School Bus Fleet Magazine Forums
Home | Profile | Register | Active Topics | Members | Search | FAQ
 All Forums
 Professional Garage
 Enter Forum: Professional Garage
 VT365 overheat problems
 New Topic  Reply to Topic
 Printer Friendly
Author Previous Topic Topic Next Topic  

Bassman
Top Member

USA
505 Posts

Posted - 05/31/2012 :  04:30:58 AM  Show Profile  Reply with Quote
Just wanted to post a tip for everyone with hot weather upon us. We are having problems with some of our 2005-6 VT365's giving us an overheat light. The diagnosis has been complicated because the fan clutches are not coming on when the bus gets over 210 degrees as they are supposed to. The cause has been the upper tubes in the radiator are clogging and not allowing coolant flow. This is troubling because only the top rows of tubes are in front of the fan clutch. If they become clogged, the air flow across the front of the fan clutch is not hot enough to turn on the clutch. Upon removal, some of the upper parts of the radiators have been so bad that even after removing the tanks, my radiator shop still can not get the tubes to open up. The deisgn of the radiator (both hoses are located at the bottom of their tanks) seems to contribute to the problem. The best way to diagnose it is to test drive the bus and pull several hills, then get out of the bus and reach your fingers through the grill and feel the tubes. If the the top 6 inches of tubes are not hot....bingo...you have your culprit.

Edited by - Bassman on 05/31/2012 04:32:04 AM

Fastback
Top Member

897 Posts

Posted - 05/31/2012 :  05:58:02 AM  Show Profile  Reply with Quote
We used to have similar troubles with our T444Es with the vertical flow "half" radiator/half intercooler. On those all our viscous fan clutches got switched to the Horton electromagnetic EC-450 clutches that operated off a coolant temp sensor in the engine water jacket.

Why yes, the ORIGinal CHARGER is a Fastback

Edited by - Fastback on 06/01/2012 11:28:53 AM
Go to Top of Page

Brad Barker
Administrator

USA
832 Posts

Posted - 05/31/2012 :  5:20:19 PM  Show Profile  Visit Brad Barker's Homepage  Click to see Brad Barker's MSN Messenger address  Reply with Quote
What kind at cooling system maintenance have you performed on these units up till you noticed a problem?

Brad A. Barker
Go to Top of Page

mastertech
Advanced Member

211 Posts

Posted - 08/06/2013 :  6:56:38 PM  Show Profile  Visit mastertech's Homepage  Reply with Quote
I came across just this problem today. It was a low mileage vt365 that never got the uptime coolant filter till last year. Sure enough the top of the core is ambient temp while the lower core is 185 degrees. good tip.
Go to Top of Page
  Previous Topic Topic Next Topic  
 New Topic  Reply to Topic
 Printer Friendly
Jump To:
 


School Bus Fleet Magazine Forums © 2013 School Bus Fleet Magazine Go To Top Of Page
This page was generated in 0.17 seconds. Snitz Forums 2000