John deere 301 running hot.

[jcharley]

I purchased a john deere 301 last year and have slowly been going through it trying to make sure everything is running properly. It had a water pump leak when I bought it but wasn't major at the time. It has since gotten worse so I have replaced it, as well as: the thermostat, gaskets and all off the hoses. I flushed the system multiple times and was very through. I cleaned the exterior fins of the radiator and vent covers as well. Afterward I filled it with fresh 50/50 coolant and test drove for a good 20 min and It was running cooler than it ever had. It was about the 3/4 on the gauge never close to red. However while cutting my pastures yesterday after about 10 minutes it would climb right to the edge of red and sit there the whole time never getting in the red but still hotter than i think it should be. I stopped multiple times to check and the coolant was still full and bright green. Maybe it's supposed to run that hot but seems it should be cooler. I don't suspect a head gasket as there there is no oil in the water or water in the oil. There is good suction pulling through the radiator and the fan belt is adjusted properly.
Again maybe this is normal but I would appreciate any and all advice.
Thanks,
Jeff

 

[beenthere]

By chance, did someone before you have a radiator leak and tried fixing it with some additive that has shut down part of the radiator volume?

Not sure how one would check that... or if it is even a possibility.

 

[jcharley]

Not that I know of, however that doesn't mean it's not possible. The person that I got it from told me about the leak at the time and said they just kept it topped off and so that's what I did until the end of the season last year when then small leak became much larger. It got to the point that it was running low while using and had to be topped of often so I replaced it. The only thing I haven't replaced is the radiator cap and it did take the full 11 qts to fill it from empty which is what the specs say it holds.

 

[Tx Jim]

I think I would check some temps of engine block,cyl head & rad with a laser thermometer.

 

[jcharley]

I will give that a shot. Is it possible for a bad radiator cap to cause it to get hot. It only got that hot under a load pulling my brush hog. Didn't get hot at all just driving it or idling.

Thanks,
Jeff

 

[Billrog]

Yes it's possible change the cap may or may not be the problem.

 

[jcharley]

I've got 1 on order. Thanks

 

[jcharley]

Well I wasn't able to put a good load on the tractor to get it hot again. We had some big storms come in and I don't want to tear up the pastures. Best I could do was hook up to the brush hog and run pto while in neutral. It wasn't enough load to get as hot as when actually mowing yesterday. It stayed right in the middle of the gauge and if my laser thermometer is correct the temps were average head 160- 185. Radiator 100-120, block 150s. I did notice that coolant was spilling out of the overflow tube. Not constantly but more than I think it should have.

 

[boggen]

not a clue about tractor. but is the carburetor setup correctly? not a mechanic.. but to much fuel gives you more power but also additional heat.

is throtle adjusted correctly (going with carb) and simply pushing tractor hard?
same with the choke for the carb/tractor?

are you putting to much coolant in the radiator? old allis chalmers 1954, if i add just a little bit to much she will send coolant out the overflow. and run a bit hot. till it gets about right.

the old allis chalmers CA also gets hot about 4 to 8 hours non stopping running. using a belly mower. and cutting tall grass. and putting a fairly good load on engine with hills and mowing the tall grass and higher gear range. simply gotta letter cool down at idle (not shut it completely off, but stop her and push throttle down to idle and let her set for some time letting the fan on engine run and water pump run to cool it all down). and then go back at it.

last time mowed. the radiator kept getting plugged up by about 1/3 grass/dust. had to keep bringing it back to the shed and using the air compressor with blow gun. or leaf blower to blow the crud out. once that was done, temp gauge went right on back down.

==========
with previous poster get a lazer gun and find out were your temperatures are.

 

[jcharley]

I haven't touched anything in the carbs so couldn't say for sure if it's all correct. It always starts right up and seems to run and idle smooth so never thought to look at it. I'll look over my manual and check into it. It was getting hot within 10 min of mowing. Pasture wasn't overgrown by any means. Speed didn't seem to affect temps and it stayed at a constant temp while mowing.

 

[Billrog]

That's the purpose of the expansion ( over flow tank ) and when it cools it siphons back into the rad. An air breather that is clean plug up with grass & dust can also cause over heating.

 

[jcharley]

This tractor doesn't have or come with an expansion tank. I understand this is how modern systems work but seems odd that they would be designed to lose coolant every time it is operated.

 

[Billrog]

That should happen only when it's filled to the top of the rad once it's found the level of expansion it should be stable.

 

[jcharley]

Ok, I'll try not adding next time and see if it stops leaking just don't want to run it low on coolant. Thanks again

 

[KWRB]

Is the radiator corroded? A heat exchanger will lose effectiveness as the material corrodes. Don't sweat the overflow. Let it do its thing and overflow. It will only do so until it has the proper amount of coolant, then it'll only expand up to (not beyond) the point of overflow. I'm actually a little confused as to why there would be a vent cap if there's an overflow tube. I'm not familiar with this particular model.

Whatever it is, it doesn't seem like a coolant flow issue, given the water circuit work you've done. It seems like poor heat transfer. Are you sure when you clean the radiator you didn't bend the fins, thus preventing proper through flow of air? Also, sometimes the dust can really pack into a heat exchanger and you'd be shocked at how solid it becomes. I like to clean mine by using compressed air blowing from back to front, opposite the direction that the radiator got dirty in the first place, rather than front to back, which just tends to jam it in tighter.

Keep us posted.

 

[jcharley]

I appreciate the advice on the overflow, I would have kept filling it up and watching it run out. I was pretty carefully when cleaning the radiator but maybe I didn't clean it as good as I needed to. I'll try to blow it out with the compressor some more. Then when the new cap comes in and the weather clears up I'll give it a good test and put a load on it to see if it gets hot still. I don't think the radiator was overly corroded, there was definitely signs of some corrosion but might be worse than I what was visible. If it's still getting hot I will see about replacing it.
Thanks again everyone

 

[KWRB]

I want to re-emphasize the importance of blowing the debris back towards the direction from which it originally came. In a conventional radiator configuration, this means blowing the air through the radiator FROM BACK TO FRONT.

Good luck.