1956 640 temp gauge

[Wavrider]

I purchased all new gauges and installed them.
Seemed to be working great until today.

I finally got the 19-105 loader on the tractor with the front root rake (came with tractor looks fabbed) and was busy plowing up old pine tree rots when I noticed the temp gauge slowly rising.

I shut the engine off and went to the overflow hose, no overflow? Raised the hood and felt the radiator cap, little bit warm but definately not hot.

I open the radiator cap, fluid level good, no steam, not boiling. startd the tractor observed the water pump was circulating yet the temp kept increasing on the gauge?

The display on the temp got to the edge of the red about the same time as the hydraulic hose busted so I parked the tractor back in the shed.

The hose is an easy fix just a trip to the local manufacturer to get a replacement but the temp gauge has me concerned. everything is pointing to a bad gauge yet it is new less that 3 hours on the proofmeter since installed.

The copper hose is wrapped in several loops between the sending unit and the gauge. Is this a possibility for an erroneous reading having the conductor wrapped in a coil?

Any ideas or thoughts will be appreciated on the temp gauge fix.

Thanks for the replies. "TO HOT IN FLORIDA".

 

[GlenIdaho]

wavrider; can't really help you other than to say I have installed a new temp gauge as well and noticed that it barely reads. Did a temp check in the radiator and it was normal temp. It leads me to believe that the after market gauges may not be so accurate. I'd start your tractor up again and watch the gauge. When, and if it begins to climb have a thermometer handy to put in the radiator tank and see what it says. If it's normal I'd replace the gauge or use it for a while and see if it settles in to nornal operation. That's what I plan to do with mine....

 

[john in la]

While it is not common; Most likely the gauge to start with; A engine can overheat or be cold where the gauge is at and not be the same in the radiator. Its called blockage.
I would take the gauge out and put the bulb in a pot of water on the stove. Then you can measure what green and what red maens in tempature for your gauge.

 

[Wavrider]

John, Glenn,

Both great suggestions thank you, I do have a digital thermometer I used for doing heating and A/C work so I will use that to check the temp next time I use the ole 640, which will be after I replace the hose, darn thing is hard to steer with that loader on it unless moving.

I do not believe it is blockage I flushed the coolant system when I got it and pulled the old temp sensor checking for flow. Doesn't mean it is not blocked now.

I reckon the other thing it could be besides the after market gauge is the water pump impellors not in that good a condition and no pressure being sent through the block.

I will do the temp check with digital read out and the hot water check to see where the gauge reads at. Thanks for the great suggestions, "DRIPPING HOSE IN FLORIDA"

 

[Steve Forrest]

Is there a thermostat in the system? Did you put it in backwards? If the temperature gauge is on the engine side it would spike like that...and you would see 'normal' temperature in the radiator.

Just a thought...don't know a whole lot about your specific machine - or my 661 for that matter!

Steve.