JD 950 over heating

[matt19370]

I’ve had a 950 with loader for 30+ years, I run a 5’ brush hog and have always had issues when it is real hot outside. keeping the radiator screen clean helps. I also installed a temp gauge to better monitor it. I use a Ford 860 for mowing now. The grass/weeds are normally 3’ tall or more when I mow.

 

[radios1]

aluminum is better at heat dissipation, which is why aluminum is used for heat sinks on electronics. copper is used as a heat spreader in that situation, particularly on CPU heat sinks. I had suggested this to a vender years ago, and a couple of weeks later, they started making aluminum heat sinks with a copper spreader for CPU's.. I didn't think about getting a patent at the time, oh well..

 

[TimberHole]

I pulled the radiator tonight. It flowed freely so I think I’m chasing my tail there. I do have a new one on the way. Also, I misspoke on the cutter. I stated I was using a 6’ cutter but it is a 5’ JD 503 cutter. Looks like my memory is marginal too! :laughing:

 

[Pkty]

Here is what I found on my Montana 3840. Removable radiator screen will stop the larger crap but I was amazed at how much dirt and dust I blew out of the fins. Made a big difference on my temps. Also another time my temps shoot up after only running for five minutes. Found that my temp gauge is secured to dash circuit board by screws. Poor electrical contact if those become loose.

 

[kthompson]

I have Kubota B2710 with HST and use a 5 foot rough cut mower. If I were to put in a 3 feet tall heavy grass at 95 degrees it most likely would run hot unless I was used low range if taking full cut width. The 950 has more hp but if you are cutting heavy grass with no breaks in the cutting for a long time, might be more than it will handle. Without reading back through each post, you have checked the mower to be sure blades are good and no issue with it turning easy would assume. Does the tractor run hot with any other work you do?

 

[stevem5215]

I had a Ford 1900 with 72" Woods finish deck. It cut great when the temps outside were colder than 80f. But as soon as it went above that I would have overheating issues out the wazzooooo. I tried everything. But it turns out that the mower deck is just too much for the tractor. The tractor of course would try to spin it and make it work but that's like the little engine that could and just made it over the top. Sure, you can do that same thing with your low hp tractor. Push it to the max but there's no warning light that goes on while at the dealership that says "you can't spin that big of a implement". We also have a FarmPro 2420 20hp two cylinder diesel that we use a 60" finish mower on. That tractor is the exact same way. It'll try and try and try to keep cutting right to the point of overheating on the gauge. But when we have used the 4' brush hog on it there's no problem at all. 48" is just enough for a 20hp that it won't overheat it and it can run all day just fine. Draw more hp and the tractor that "could" will turn into "can't".

Steve

 

[rScotty]

I pulled the radiator tonight. It flowed freely so I think I’m chasing my tail there. I do have a new one on the way. Also, I misspoke on the cutter. I stated I was using a 6’ cutter but it is a 5’ JD 503 cutter. Looks like my memory is marginal too! :laughing:

Hmm.... my bet was on the foam strips that mount between the radiator and the shroud and direct the air to have to be pulled through the radiator instead of air sneaking in from the sides of the radiator fan.. Yanmar published a techincal paper on that very problem that applied to their YM336 - which is the same engine and cooling setup.

When you install the new radiator, pay good attention to getting a nice seal on those foam strips along the edge of the shroud.
rScotty

 

[TimberHole]

I have a partial update. Ran the tractor today after installing new radiator, new exhaust, new OEM thermostat, new air filter and new OEM radiator cap. Tractor stayed cool. Temp stayed about 165 when not working and about 175 under load. It returned to 165 after working when left to idle. I also changed to a 70/30 mix. I did see a slow bubbling in the reservoir so I do think I have a tiny head crack that contributed to the problem. It was 6 or 8 degrees cooler today and I was using a 5’ tiller instead of a 5’ rotary cutter. I think the cooling system is functioning correctly now and I believe this tractor will easily run a 5’ cutter in 90 degree temps. Generally speaking I think the overheating issues with these compacts is often a combination of issues.

 

[TimberHole]

70% water. I’ll switch it out as soon as it cools off. Next year with my issues resolved I’ll go back to 50/50 and try again. Right now I just needed to get some work done so I threw everything but h th e kitchen sink at it. The good news is I am convinced the cooling system is adequate for these hot summer days.