Cooling system diagnosis

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Oct 23, 2015 | 01:25 AM

johnwassink

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Senior User

Joined: Mar 2013

Posts: 203

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From: Clarence (Buffalo) NY

Cooling system diagnosis

Hey guys, I got a 92 f450 dump and am trying to figure out what the problem is w/ the cooling system. The truck is new to me and my mechanical knowledge is limited.
First off, the gauge does not work and sits all the way to the left even after warm up. It doesn't seem like the thermostat opens at all even after warmup. The upper radiator hose will get hot, the lower one stays cool. There's heat in the cab. The waterpump seems to be working as the level in the radiator will drop go down while revving. The coolant is clean and I don't think there's air in the system, I parked it on an incline and let it warm up, milked the radiator hoses at times, no air release. My buddy replaced the waterpump, last year, not the thermostat though. I haven't had an overheat situation, but normally only drive the truck about 9 miles one way to the landfill.
What should I do next?

Oct 23, 2015 | 03:58 AM

jaagen

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Joined: Jun 2012

Posts: 463

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From: Rohnert Park Ca.

I would replace or even test the t-stat. You can try running without it.

Oct 23, 2015 | 05:44 AM

tjc transport

i ain't rite

Joined: Mar 2005

Posts: 65,492

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From: Marlboro Mental Hospital.

take the wire off the sending unit and ground it out. the gauge should pin on hot. if it does, the sending unit is bad. if it does not, the wires going to the gauge or the gauge are bad.