Hi After replacing the missing glass panel in the door, I’m trying to get the heater working in the cab. - The fan/blower works - The heat on/off pull cable and valve were lubricated and seem to be working. - when I got it, Both cab heater lines were cut near the starter. I randomly reconnected the lines but didn’t know if the order is important, does the direction of coolant flow matter? - There is a square socket head nut near the water pump (picture). Someone told me this nut controls the cab heat flow, can anyone comment on this? I let the machine idle and warm up until the top radiator hose was warm but no heat felt in the cab. It may take longer than I expected or a mud dauber wasp could have plugged up the open coolant lines. Any thoughts on this ?
That is a plain ole pipe plug in the picture. You proly need to do some research in the parts book. there are variations of the hose routing. Go here for a start. https://www.mycnhistore.com/us/en/c...assis/cn/51EE0978-8FBF-E111-9FCE-005056875BD6
Tinkerer, after looking at the parts diagram I see they are very specific re the hose routing. Will check it . Thanks.
Typically one of the heater hoses will return to near the water pump inlet, and one will supply from near the water pump outlet. You need a pressure difference to get circulation, and the water pump is the only pressure difference you have. Do you have a good thermostat, does it reach 180 degrees? The order of connection shouldn't matter much if the original heater valve were still in place, I was thinking maybe you added new adapters for the heater hoses. That plug is not a valve, could be a port for the heater hoses if they were missing. Wouldn't hurt to remove the hoses at the engine and blow them out with water and/or air pressure.
On a 580M, engine right side (don’t have a pic) is a valve that is turned closed (clockwise) for summer and same valve turned counter clockwise when heat needed in the cab. this may have been what you were referring in the post.
Heater core may be plugged.
Ok , all good feedback, thanks. Thinking of what would be the easiest way to go about this. As mentioned by Delmer , until the coolant is 180F , no coolant will circulate into cab circuit, I think this is the starting point. Then I’ll look at clogged lines etc. The thermostat is probably at least 5 years old so it could well not be opening.
No, coolant will circulate as soon as the engine is running, even if that coolant is still -30. If there is no thermostat, then the pressure will be lower. If the thermostat opens too soon, then the temp won't get high enough to get good heat, but if you work hard you should still have plenty of heat. You won't get good heat if the engine is just idling with a thermostat stuck open. 1. check that the engine gets warm before the radiator top does 2. with a warm engine, both hoses should be warm if there's no fan running but the valve open. One will be slightly cooler if the fan is running and putting out heat. If not, there is no circulation through the heater hoses and heater core, find out why.
I have a 580SE, the inlet (hot) hose for the heater comes from the top of the engine near the thermostat, the outlet (cold) hose attaches just below the pipe plug you have pictured in your post. The hoses attach to the tubes that runs up the left side pillar of the cab. The hot hose connects to the front tube and then the cold hose connects to the rearward tube. You can get free shop manuals, parts manuals, and operator manuals for your 580SE at Minnpar.com, I just downloaded my a week ago. They are free. Page 654 of the shop manual shows the hose routing, you will see what I mean. Like you said you may have a blockage in the system, probably need to flush it out. Sounds like the heat pull on/off is working ok, mine is currently seized. That square socket head nut (plug) is actual the engine drain plug, if you take it out it flushes all the coolant out of the engine. Cheers
If the heater core is higher than the engine, like the roof of the cab, then you might need to rev the engine to full speed to get the coolant to burp the air out of the hoses and heater core.
Welcome to HEF , Old Eng !
Thanks Tinkerer. I have a couple old backhoes so I imagine I will be visiting frequently. Hopefully I can help out a few members along the way. Cheers
Got Heat !! Yesterday I drove the backhoe around and got it warmed up and the heat started flowing out of the blower. This is a real milestone in the restoration progress on this backhoe... after: - fixing door and replacing glass - removing headliner and fixing radiator core flow valve - reconnecting two coolant lines to cab - dismantled, cleaned contacts on magnetic switch that Provides 12v to accessories like blower ....the heat in the cab is flowing!! Next I’d like to get the water temp gage working. Can someone tell me where exactly to find the water temp sensor. I think it’s on the left side around middle of cylinder but I’m not sure which is oil temp, water temp etc Thank You !
The water temp sensor (or sending unit) is at the front of the engine just above the thermostat. It actually screws into the housing that the thermostat is in. If you want to test the sensor you can remove the wire connected to the sensor , turn the key to the on position (don't start the engine) and touch the sensor wire to the engine block, when you do this you need someone to watch the the gauge in the cab to see if the gauge pivots fully to the high temp position. If the needle moves you know the sensor is not working, if the needle does not move either the gauge is faulty, or the wire from the sensor to the gauge is broken. The way the sensor works is that as the sensor heats up the resistance inside the sensor decreases which causes the needle to move. When you connect the wire to ground and bypass the sensor you are just simulating zero resistance in the sensor. One thing to check is that someone did not wrap a ton of Plumbers Tape around the sending unit threads which is preventing the sending unit to ground properly. I have the same problem with my 580, when I shorted the sensor wire I get full swing of the gauge, also as I heat up the sensor I do see the resistance dropping with my multi meter, so I still have some homework on my machine as well. Cheers
I believe the picture that you posted is the engine oil pressure sending unit (item 39 on page 102 of the shop manual). It works similar to the water temp sensor that I described above. There is also a shuttle transmission oil temperature sensor on the shuttle unit under the cab (item 20 on page 120 of the shop manual). Cheers
Thanks for all that. I found the sensor unit hidden on top where you said it was. - removed the wire and clipped it to ground. Then with key in on position l looked a water temp gauge but no visible movement of dial pointer occurred. - with wire off sensor, I measured the resistance between sensor and ground , result on cold engine: 6.81k OHM. I assume this is within a range for a functional sensor. Next test will be to see if there is continuity between the wire at the water temp sensor and the corresponding copper tab on the console connector plug.
You are on the right track. I just measured an old water temp sensor for my 580 that I had in the garage for reference and it was 5.27k OHM, the sensor was about 40F when I measured it. Not sure what the spec is for the sensor. Hopefully you just have a continuity problem in the wire, you can also run a temp ground from the console connector plug and see if the dial pointer moves.
Eureka ! It turns out that the little copper foil tab #10 on the female connector on back of instrument cluster was bent to the side. I carefully repositioned it and water temp gauge responded. I think it’s fixed, will know for sure one I get a chance to really do some work and get it hot. Thanks.
That's awesome, good find!
Thanks for the details on fixing the heat issue..
Welcome to HEF, Roger !
Thanks Tinkerer, Would I find issues like cab heat restoration for JD tractors made in the 1990's in a sub group of HD equipment? Or are they not that specific to make and model?
If the tractor was available with a cab heater, all the parts should be in the JD parts book. Salvage yards are another option if you have the time to send a lot of emails or make phone calls. If it wasn't an option an aftermarket heater can be installed. I put one in my T/L/B and it was an awesome addition ! Post the tractor model and I'm sure the HEF'ers here will help you.
I have a 580 SE and I'm having trouble with the heater motor in the cab, when I turned it on to high it would blow the fuse so I took the resistor to a shop and had it tested and it was blown so I replaced it and tried running the heater again on low, it turned on very very slow when I turned it to the second position I saw smoke coming out of the resistor so I turned on high and immediately blew the fuse, I cannot see how this motor is grounded can anybody give me some information.
Dry bearings in the motor may be the problem. Remove it and try to get some oil in them.
Amen to that , try and spin the fan with your finger and see if it turns easily and will spin. If the fan is hard to turn and wont spin easily, that's your problem. Maybe if you can shoot some lube on both bearings it will loosen up. Otherwise you'll have to remove it and pull it apart and clean up the shafts and bearings and add oil or grease. Then it should be fine.