How to tell if B7100 is overheating

chetcromer

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Equipment
1981 Kubota B7100 4WD
Hi all. I've been away for a month while I got the steering gear box of my B7100 repaired. During that time my pastures did not stop growing, so when I got it back I had a mess of tall grass and weeds to chop down. I have a 5' Woods finish mower to do the job, and it is doing great if I raise the deck just a bit off the ground on the first pass.

All that said, how do I tell if my tractor may be running too hot? No gauges at all. I shut her down early today because the (makeshift) overflow container that the radiator flows into as needed got too full and dumped a splash of coolant onto the engine. So I shut her down to let everything rest. Sounds of gurgling (boiling?) coming from the radiator as well (50/50 water/coolant).

Is there a way to know when I'm pushing the tractor too hard? Smokes just a bit, but only when first starting; past that it's barely even bogging down unless I hit a very tall patch of heavy weeds or grass.

I'd appreciate your input. Thanks.
 

hodge

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You could install a temperature gauge, or what I do is use an infrared thermometer and check the head/exhaust manifold/radiator hose. It's been a while since I've done it (out of curiosity), but it works well.
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
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I have heard that some of the B7100's had a "whistler" on the radiator overflow but mine doesn't have one.

One thing that an make them run hot is the radiator fins or screen get plugged with debris. Just make sure they are clean and breathing.

I've see where a dirty and plugged air cleaner can also make them run hot too.

If you do decide to add a temperature gauge to it make sure you use a BSP fitting (British Standard Pipe), it's not the same thread as standard pipe thread.
 
Last edited:

Morgan44

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Jul 7, 2013
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Walton KY USA
I've been thinking about putting a temp gauge on my b7100 also. You mention that about the threads, where would this actually tap into to? I'm trying to figure out where to mount a gauge and where and how this would actually work.
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
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That can get a bit tricky, they are all different, some have plugs that can be removed to install the sending unit.
With some of them you will need to install a tee off of the radiator hose.
 

chetcromer

New member

Equipment
1981 Kubota B7100 4WD
Any recollection of the temps you would see using the infrared?

And is the boiling normal? I'm just not sure how hot thing thing should be running. It doesn't seem mind the work, but the cloud of smoke when the coolant splashed on the engine got me thinking I'd better put a little thought into it... I've been working on this tractor for 2 months now and am ready to not do so until the winter again. :)
 

hodge

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John Deere 790 John Deere 310 backhoe Bobcat 743
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Boiling isn't normal- you should check the fins of the radiator (which are prone to get clogged with debris, like any radiatior. But, due to slow speed, it is more crucial that they stay clean), keep those cleaned out, and maybe even service the cooling system. Your tractor doesn't have a water pump, but instead uses convection. It works fine, but a clean system is important to the easy flow of coolant.
I would see high 170's for coolant, in the 190's for the exterior of the cylinder head, and mid 200's for the exterior of the exhaust manifold.
 

skeets

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BX 2360 /B2601
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And I would presume that your using a 50/50 mix in there too,,,eh