Poor cab heat

[dirtworksequip]

radman, what was the vedict on your no heat situation?

 

[radman1]

You guys actually gave some good suggestions. I will recheck the AC knob to be sure it was turned down and try other settings. I still cant explaing the rapid condensation on the window. I was in the cab about 10 minutes before turning on the heat with no fogging. Turned on the heat, and the condensation was so heavy in 1 minute, I could barely see out the windows and it was almost ready to run down the glass. I had to open the door slightly to stop from drowning.
It is cool again to night so I will go try it again. I will look for any shut off valve and check the temp of the hoses. Maybe I will even get desperate and read the manual. I will post back my findings. As I predicted, dealer never called back. Dementia?

 

[radman1]

Just returned from second try with the heater. Same as last time - poor heat. Heat gauge needle only rises about 1/4 to1/3 up in the green range from the bottom. It is about 45 outside. At fast idle took about 10-15 minutes before heat gauge needle moved. Ran the tractor for over 25 minutes. The heater hose going to the heater and return hose get warm to touch but I would guess less than 90-100. AC completely turned off. No shut off valve on heater hose (although I think this maybe a good ideal in the summer). No condensation in the cab but I stayed outside mostly unless just checking the heater output.
My guess is the thermostat is faulty or stuck open. Anyone else agree/disagree or any other suggestions?
By the way, read the manual. Not real helpful. What is the deicer switch suppose to do? Is this to prevent fogging in the cab?

 

[tglass]

Doesn't sound like the thermostat is stuck. That's about the temp when mine gets warmed up. With that little hours Id'e call the dealer for some warranty work. At least a mech. to stop by at no cost to check it. Although mine is a little loud inside, (I know, quieter than kabota, but still loud compared to const. equip.), the heater and a.c. will make you turn in down in any weather. Time to CALL THE MAN. Let us know what they say.

 

[radman1]

Doesn't sound like the thermostat is stuck. That's about the temp when mine gets warmed up. With that little hours Id'e call the dealer for some warranty work. At least a mech. to stop by at no cost to check it. Although mine is a little loud inside, (I know, quieter than kabota, but still loud compared to const. equip.), the heater and a.c. will make you turn in down in any weather. Time to CALL THE MAN. Let us know what they say.

I called the man today. Will drop it off tomorrow. Need to get it checked out before cold weather comes. To me, the heater hoses should be too warm to touch when just coming off the radiator.

 

[radman1]

Update. Took tractor back to dealer. They called and said heater was putting out temp of 100F. Thought maybe I had the AC on with the heater. I said I checked it twice to make sure the AC was off and still poor heat. I told him the heater hose off of the radiator was barely warm to the touch after running tractor 25 minutes on a 45F night. I then asked them, "Did you check the tractor outside of your shop?" He said no. Duh! I told them to recheck it outside where it is colder. He said the thermostat is 77 celcius which converts to roughly 170F. Seems a little on the cool side to me. I'll wait for next update tomorrow.
Can the radiator temp be checked directly? I assume since they can check the heater air temp, can't the radiator temp be checked?

 

[radman1]

Update. Talked with service manager. He agrees that the heat coming out is poor. He talked to JD and there is a known problem on the 3720 because of larger radiator on that model, due to turbo with intercooler. Radiator doesn't get hot enough. JD is working on a fix. For now he suggested to use the "cardboard in front of the radiator" trick until problem is solved. This is not a great solution for a $30,000+ tractor.
Does anyone else have this problem with a 3720 cab? If not, when did you buy it?

 

[radman1]

Update #3. Went to pick up tractor. Long discussion with service manager. They completely blocked off the radiator with a piece of cardboard and cab heater put out 100-110F. The higher temp was measured with only one vent open and driving the tractor around with engine speed to 2500 rpm. Essentially no heat. With the radiator blocked off, the engine block measured by their gun was 125F. Removed thermostat and checked it in hot water. The thermostat is set at 70C (about 156F) which is recommended by JD and the thermostat is opening and closing properly when placed in hot water. The measured temp at the top of the radiator was 77F with radiator blocked off. (outside Temp is 55F).
He talked to Jd service. He says most times when he calls with a problem, they usually tell him, "Never heard of that." This time JD service new of this problem and engineers are trying to come up with a fix. JD service is hearing this also from other dealers and it is a problem on all the 3000 twenty and 4000 twenty cab tractors. My service manager said in the past few days he now has 3 customers with the same complaint. He expects more to be calling. I told him others with JD cabs on the internet say they don't have any problems and these tractors have been out over a year. He also says he has not had this problem until now. What JD won't tell my service manager is if there has been changes in the cooling system in the past year. My guess is the cooling system was changed relatively recently and this problem is now just surfacing. Was there an overheating problem with these series and cabs? He knows I not happy with this situation. When I bought the tractor, I was more worried about over heating with the AC coils and intercooler sitting in front of the radiator. Who would of thought the opposite would be the problem.
My thoughts are maybe the fan needs to have a thermostatic clutch instead of spinning all the time. Hotter thermostat may help but if the enging block is only 125F now, I would guess the thermostat is closed all the time in the current situation. Smaller radiator, but will that be a problem in the summer? Any other thoughts?
I just left the tractor with them and currently frustrated with JD. New Kubota models are looking better.

 

[NoMo]

The observations make sense. The radiator can't get hot (even when blocked) because the engine is never heating up enough to cause the thermostat to open.

Sounds like it's going to be a difficult fix. Since I'm not familiar with diesels at all, I don't know how you could get one to run warmer other than by working it harder. And, if they do get it to run warmer, will it overheat in the Summer!?!

Good luck- and keep us updated.

 

[TCowner]

I've been follwing this post closely as my brother is in intense negotiations with his JD dealer for either a 4520 or 4720 with a cab.

I must not understand the process of bringing a new tractor, accessory or attachment to the market because I just can't grasp why a manufacturer wouldn't have caught a problem with poor heater output in a $6,000 cab prior to production.

Deere produces some of the finest cabs in the business. The factory cab on the 5000 series tractors is incredible. I trust Deere has a cold weather test lab at their disposal where a 3000 and 4000 series tractor could have been tested at 20 below zero to make sure the heater blows hot air. In Minnesota the heater in $6000 cab is just important as the AC.

I've been critical of New Holland because of their delay in getting a factory cab to the market place for compact utility line. The new cabs are supposed to be at the dealers very soon. If New Holland did their homework and has a cab that has a heater that heats and a air conditioner that cools then they should be congratulated for waiting until it was done properly. It irritates the heck out me that manufacturers use their paying customers as their troubleshooting and testing department.