2011 DK45SE - Do I need more tractor?

[hypotenoose]

I have a 6' rotary cutter. I have about 26 acres of land to keep clear. Much of it is hilly. My guess is that some hills have 30+ degree slopes. But, that might be off. Just he same, I live in Kentucky. So the summers can be pretty hot and humid at times. Some of the hill runs are 150 yards from base to peak. I haven't used the tractor on some of the hills until this year. I noticed today that the coolant temperature gauge was nearing the red region when I got to the top. On the run back to the bottom the gauge would make its way back to the normal zone. I noticed the coolant boiling in the reservoir as well and had to top the reservoir off today. All indications are fine with regard to air flow. I am quite careful about not letting the RPMs get above what is rated for my rear PTO. Not sure what might be wrong. But, I sense that maybe my tractor just might not be enough for my needs. I am hoping someone will reply with an obvious operator error!

 

[k0ua]

I have a 6' rotary cutter. I have about 26 acres of land to keep clear. Much of it is hilly. My guess is that some hills have 30+ degree slopes. But, that might be off. Just he same, I live in Kentucky. So the summers can be pretty hot and humid at times. Some of the hill runs are 150 yards from base to peak. I haven't used the tractor on some of the hills until this year. I noticed today that the coolant temperature gauge was nearing the red region when I got to the top. On the run back to the bottom the gauge would make its way back to the normal zone. I noticed the coolant boiling in the reservoir as well and had to top the reservoir off today. All indications are fine with regard to air flow. I am quite careful about not letting the RPMs get above what is rated for my rear PTO. Not sure what might be wrong. But, I sense that maybe my tractor just might not be enough for my needs. I am hoping someone will reply with an obvious operator error!

Clean the chaff out of the radiator. Also what range were you in? I hope not higher than MED, and if the hill is really steep then LO. But the main problem is your radiiator is stopped up by debris. You will need to clean it every few hours if your mowing some really heavy stuff. This would be my best guess as to what is wrong.. Tractor is fine size wise. The other possibility would be a blown head gasket, Possible of course, but take a look at that rad.

 

[hypotenoose]

Clean the chaff out of the radiator. Also what range were you in? I hope not higher than MED, and if the hill is really steep then LO. But the main problem is your radiiator is stopped up by debris. You will need to clean it every few hours if your mowing some really heavy stuff. This would be my best guess as to what is wrong.. Tractor is fine size wise. The other possibility would be a blown head gasket, Possible of course, but take a look at that rad.

Thanks K0ua. I really appreciate your response. I ran it in LO on the hills. I will clean out the radiator. Hopefully that is all that is required. I noticed some debris in the reservoir. By the way, it the cooling system is fine should the gauge still read normal temperature on big hills if I am running at the proper RPMs (in low of course)? Or, should I expect it to run hot under some conditions? Thanks again for the information.

 

[k0ua]

Thanks K0ua. I really appreciate your response. I ran it in LO on the hills. I will clean out the radiator. Hopefully that is all that is required. I noticed some debris in the reservoir. By the way, it the cooling system is fine should the gauge still read normal temperature on big hills if I am running at the proper RPMs (in low of course)? Or, should I expect it to run hot under some conditions? Thanks again for the information.

I have never seen my Dk35se run hot at any time. Even climbing very steep hills.

 

[SSdoxie]

Chaff in radiator, especially when mowing, is #1 to check.

I have encountered 2 Bobcats, a 45 & 50, that had same problem of overheat when worked hard but ran fine otherwise. Found the thermostat had gotten bent during installation and wouldn't open fully. If all else fails check it.

 

[motownbrowne]

You said you don't let the rpms get higher than the 540 PTO speed, but you didn't say if you were operating below 540 PTO speed. These modern diesels like high rpms and will cool better at PTO speed. If you're running below that, crank it up to 540.

 

[grm61]

Yep blow out the radiator fins and all screens, you'd be amazed how much dust and dirt come out the radiator fins after just working a few hours in dusty conditions.
The debris in the reservoir does not sound good,. What kind of debris?
Also factory recommends coolant change every 2 years

 

[kco]

Yep blow out the radiator fins and all screens, you'd be amazed how much dust and dirt come out the radiator fins after just working a few hours in dusty conditions.
The debris in the reservoir does not sound good,. What kind of debris?
Also factory recommends coolant change every 2 years

This reminds me that I am overdue for replacing the coolant.

As grm61 says, the debris is not a good sign and may indicate that the system is dirty on the inside. I bought a used car long ago that would not put out heat in the cold Manitoba winter. Piles of gunk came out when we flushed the cooling system. It worked great after that.

Similar to what k0ua said, my DK35 never strays from the narrow range in the guage's mid-marks--summer or winter. I'm impressed how well it holds in that narrow range.

 

[k0ua]

I wonder how the original poster made out.

 

[Jose G]

maybe there is a small leak, or bad Radiator Cap... the coolant need to be pressurised in order to not boil.

personnally, I have a 6 foot bush hog and the only thing I hate about it on my trator is when I hit the PTO switch (implement raised), the engine nearly stalled the first time... now I hit the switch @ 1800-2000 RPM but still loosing about 1K rpm... (glad I didnt choose the 7 footer!)

other than that, I sometime have to be gentle on the HST pedal when on medium gear or simply put it in low gear to get up a ~40% hill while mowing. (when mowing, I always make sure my RPM is right on the PTO arrow)

 

[MotorSeven]

Not just chafe...between the rad and the oil cooler is perfect space for mouse houses. You can't see them from any angle, but get a powerful hose nozzle and spray water from the front and the rear working your way over the whole rad. I had the same problem and I had already cleaned out the chafe. When I got to working that high pressure water in there I flushed out a softball sized nest....now no more overheating.

Also, never clean chafe with the engine running, even at idle the fan sucks all the stuff you knock off the screen right into the fins.

 

[hypotenoose]

I really appreciate all of the responses. I am about an hour from my tractor during the week. I am headed back this weekend with my gas powered leaf blower to try and blow off the rad. I don't have running water at the property (yet). Thinking about buying an air compressor to help me keep the radiator clean in the meantime. I have kicked a couple mice nests off the top of the radiator area. Funny you should mention, because the first time I stopped to pop the hood after 3 hours of mowing, having noticed the heat gauge, a mouse came out from UNDER the radiator or so it appeared. I have no idea how that thing was still alive as the engine was putting off loads of heat.

As for the boiling coolant, is that a definite sign that I have bad pressure in the coolant system? The tractor only has 100 hours, has been running great and I had all of the fluids changed last year at my Kioti dealer right at 50 hours. Now I am a little stressed thinking I didn't catch the engine temp in time to prevent more damage. Won't know until I am back this weekend. Wish me luck!

 

[4bama1]

To clean the radiator good you will need a hose with some pressure but not to much or you will bend the fins...Air pressure will do some good but the water will do a better job..Also check your air filter.....

 

[hypotenoose]

I made a run out to my tractor this evening. I spent some time cleaning the screens and blowing out the chaff with a leaf blower. I got most of it blown out. Would need more directional pressure to blow out the little I saw remaining. I mowed for about an hour on gently rolling hills then headed for the steeper hills. The coolant gauge did not budge away from the narrow normal range. Looks like that did the trick. I took a closer look at the coolant reservoir for the debris I thought I saw. Turns out there were tiny specks of grey - almost like super soft putty - near the inside top of the reservoir stuck to the side. I could not see anything floating in the reservoir and the coolant looked clean. Could the boil off of coolant that I saw when the tractor was running hot have yielded this "residue"? The oil level is fine and no air bubbles, so I do not think there is any interaction between the rad fluid and engine oil. Again, the tractor mowed for an hour tonight with a perfectly normal coolant temperature.

 

[k0ua]

I made a run out to my tractor this evening. I spent some time cleaning the screens and blowing out the chaff with a leaf blower. I got most of it blown out. Would need more directional pressure to blow out the little I saw remaining. I mowed for about an hour on gently rolling hills then headed for the steeper hills. The coolant gauge did not budge away from the narrow normal range. Looks like that did the trick. I took a closer look at the coolant reservoir for the debris I thought I saw. Turns out there were tiny specks of grey - almost like super soft putty - near the inside top of the reservoir stuck to the side. I could not see anything floating in the reservoir and the coolant looked clean. Could the boil off of coolant that I saw when the tractor was running hot have yielded this "residue"? The oil level is fine and no air bubbles, so I do not think there is any interaction between the rad fluid and engine oil. Again, the tractor mowed for an hour tonight with a perfectly normal coolant temperature.

Glad to hear you are going good now. See you don't have to trade off the tractor, just blow out the radiator! I don't know what the little gray flecks are, but just a guess that they may be from the water pump lubricant that sometimes manufactures put in the coolant. Water pump lubricant is a gray viscous fluid. Perhaps the high heat stress caused some of that to precipitate out of the coolant solution?.. Just thinking out loud here, I don't really know. Keep in mind that rad can stop up rater quickly again depending on how dusty your materiel is, and also the outer grill can stop up pretty quickly too, and require cleaning also.

 

[MotorSeven]

all rodents must die.........

 

[k0ua]

all rodents must die.........

Or at the very least stay the heck out of our tractors...:laughing: