Poor cab heat

[JasonMac]

My 3720 Cab will heat up to a comfortable warm temperature within' five minutes of idle time on a 32 degree night. Now that is five minutes from cold start to warm temperature. What I mean by cold start, is the tractor has been sitting outdoors, not in a heated garage. But once I get the tractor moving and the hydraulics running, I have to turn the heat down half way or it gets too hot....

I can't understand why they can't figure out your machine, something is obviously a lemon on the system, and I don't know why they can't figure it out. They know how it works, they build them????

 

[gemini5362]

I have a question that just occured to me. Does your heater hose inlet come before your thermostat and your outlet after it? I am wondering if they have the heater core bypassing the thermostat houseing ?

 

[radman1]

I have a question that just occured to me. Does your heater hose inlet come before your thermostat and your outlet after it? I am wondering if they have the heater core bypassing the thermostat houseing ?

The heater hose coming in T's into the lower radiator hose before it even reaches the water pump. The lower radiator hose then returns to the water pump and circulated through the block. The outlet heater hose comes off the top of the water pump just before but adjacent to the thermostat.

 

[radman1]

My 3720 Cab will heat up to a comfortable warm temperature within' five minutes of idle time on a 32 degree night. Now that is five minutes from cold start to warm temperature. What I mean by cold start, is the tractor has been sitting outdoors, not in a heated garage. But once I get the tractor moving and the hydraulics running, I have to turn the heat down half way or it gets too hot....

I can't understand why they can't figure out your machine, something is obviously a lemon on the system, and I don't know why they can't figure it out. They know how it works, they build them????

Your is exactly how mine should work. Thats how all of them should work. Something is wrong and they just can't figure it out. Turbo 36 has the same problem.

 

[turbo36]

Your is exactly how mine should work. Thats how all of them should work. Something is wrong and they just can't figure it out. Turbo 36 has the same problem.

My dealer is scheduled to remove the roof and check the insulation and seal today, I will let you know what he finds.

 

[gemini5362]

The heater hose coming in T's into the lower radiator hose before it even reaches the water pump. The lower radiator hose then returns to the water pump and circulated through the block. The outlet heater hose comes off the top of the water pump just before but adjacent to the thermostat.

Ok so if i understand it right then the block water is circulated through the heater core before the thermostat. so while the thermostat is closed the block cooling water circulates through the heater core like a small radiator. Now one of the things I am not clear from your reply above you mention that the outlet comes off of the water pump just before but adjacent to the thermostat. does that mean that it goes through the thermostat or that it bypasses it.

It would seem to me that if there was some way of putting a thermostat in line with the heater hose that all your problems would be resolved.

 

[radman1]

Ok so if i understand it right then the block water is circulated through the heater core before the thermostat. so while the thermostat is closed the block cooling water circulates through the heater core like a small radiator. Now one of the things I am not clear from your reply above you mention that the outlet comes off of the water pump just before but adjacent to the thermostat. does that mean that it goes through the thermostat or that it bypasses it.

It would seem to me that if there was some way of putting a thermostat in line with the heater hose that all your problems would be resolved.

The outlet hose come off the top of the water pump. The outlet is part of the water pump. As the water pump spins, water is always going into the outlet radiator hose regardless of engine temp and to the cab. The thermostat is basically a second outlet on the water pump and idependant of the radiator hose outlet. Water only pumps through the thermostat outlet and to the radiator if the engine temp gets hot enough to open the thermostat.

 

[radman1]

Update. Tractor has been at 2nd dealer for two days. They also have a 3720 cab on the lot. It behaves just like mine and maybe worse. It has never had a cab stereo put in. They took the top off mine and the roof seal seemed to be OK. Service guy tried to imply that is just how the cab tractor's heat. I didn't buy that line. They also don't know how to fix it. The regional rep is pushing for changing the injector timing but I don't want to go there yet.

 

[dirtworksequip]

radman, 24degrees F tractor stored outside.

6:55AM glow plugged for 10 sec-tractor started at fast idle.
heater temp knob set to high -fan off
checked for heat from vents every 5 minutes at idle with fan on high.
6:56 NO HEAT
6:57 NO HEAT fast idle shuts off.
6:58 NO HEAT
6:59 NO HEAT
7:00 NO HEAT
7:01 NO HEAT
7:02 NO HEAT
7:03 NO HEAT
7:04 NO HEAT
7:05 NO HEAT
7:06 NO HEAT
7:07 NO HEAT
7:08 NO HEAT
7:09 NO HEAT when fan is switched on air is warm,but cools with fan on.
7:10 NO HEAT " " " "

I probably could sit here all day idleing and the cab temp wouldn't change much,but 15 minutes is long enough.
7:11 ran tractor back and forth in driveway working the front blade and simulating work. I had heat in 5 minutes!

I just cannot understand how you expect your tractor to throw heat without some work load on the engine.
I'm completely satisfied with the heating system on my 3520. It functions just how I anticipated it would.

I also currently have 3 Cat machines. The heating systems on them work the same as the Deere tractors.NO WORK=NO HEAT!

Do you think something is wrong with my 3520 and Cat machines? I'm not trying to be confrontational. I just think you are expecting your tractor to do something it can't.

 

[dirtworksequip]

radman, its going to be colder tonight and in the morning.Low 20's to high teens. I'm going to plug in the block heater and start and run as I normally would. I'll let you know how quick or slow that I have heat.