790 JOHNDEERE

[DEEMEESE]

Bottom radiator hose stays cold top hose is hot tractor does not overheat???any ideas thanks Dee

 

[Willl]

,

Bottom radiator hose stays cold, top hose is hot, tractor does not overheat???, any ideas???, thanks Dee

Sounds like it isn't warmed up enough to open the thermostat.

Are you having any problems with it ?

 

[pedalstomper78]

Radiator getting warm also? What is the gauge on the tractor saying?

 

[DEEMEESE]

Hey thanks No problems ran it for a half hour or more loadin firewood,,,felt the hose cold on the bottom warm on top hose..Reason i checked i had to add alittle antifreeze to the overflow resevoir ??but no overheating problems ?/

 

[DEEMEESE]

Temp gauge stay in the green way down in the green never gets even halfway up the guage

 

[arrow]

This is quite common. I believe the JD stat opens at 160*. I changed my stat recently and my bottom hose is still cool to the touch. My top hose isn't that hot either.

 

[DEEMEESE]

Thanks may be that ,,,

 

[pedalstomper78]

I would go with the tractor isn't running that hard and is just using a wee small bit of the capacity of the radiator. Run it and have fun. The only way that I would be concerned was if it was heating up on ya.

 

[crashz]

My 770 does the same thing. I replaced the thermostat, coolant, temp sensor and hoses. Still, it only creeps up to about 1/4 of the way when working in the summer.

 

[kebo]

Welcome to the forum Dee.

Never had any troubles with my 790 in the summer, it runs just fine!! Now the operator has nearly croaked a time or two in the 98 deg weather lol. To be more serious, I've never felt the hoses on mine after running it a while, but now you got me wondering and I will check it the next time I've had it running for a while.

Btw, in case you aren't aware, there's a simple little trick you can do to the 790's to increase the hydraulic pressure. The hydraulic relief valve is set to 2000psi at the factory, but it can be safely increased to 2500 psi and give you a little more lift capacity on the loader (if yours has one) and on the three pt lift too. I did it to mine, and it makes a difference. If you're interested, there are several threads on it and you can use the search function and you should be able to find some of them. Basically it involves adding some shims that you can get at your JD dealer for about $10 bucks.

 

[mowin]

I'm not too far from ya, and It was cold yesterday. Wouldnt be suprised if the tractor never got warm enough for t-stat to open...

 

[RoyJackson]

My 770 does the same thing. I replaced the thermostat, coolant, temp sensor and hoses. Still, it only creeps up to about 1/4 of the way when working in the summer.

My 790 was the same...as was my old Deere 670 and my current Deere 4400. All ran cool (about 1/4 in the green) even when mowing, brushcutting or chipping at PTO RPM

 

[crashz]

I should mention that I replaced that stuff to eliminate the added heater from the previous owner and for PM. It is an early model (1989) 770, and I wanted to make sure the cooling system was well maintained.

The previous owner installed a heater into a homemade cab (Extremely Thrifty) and temps would never even register on the gauge. The heater, which was fed from the tapped radiator hoses, was about 1/2 the size of the radiator and would barely get warm to the touch. I felt that this was bad to run the tractor so cold ( would consistently smoke at idle) so I removed the heater and everything else besides the canopy. Once the cooling system was returned to stock with new parts, the tractor began running better and quit smoking.

 

[DEEMEESE]

Thanks guys

 

[Hooked_on_HP]

The hot water from the engine returns to the radiator through the top hose, passes through the radiator and is pumped back through the engine through the lower hose. So if your cooling system is working correctly the lower hose should be a lot cooler than the upper.
Bill