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Block Heater Install on 941 Loader

Discussion in 'Track Loaders' started by Metalman 55, Nov 8, 2018.

  1. Metalman 55

    Metalman 55 Senior Member

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    On my old 941 Loader with the D330 engine in it I want to install a block heater to assist with winter starting, as this machine is always accessible to plug ins. Wondering if there can be any advise given where the best tap in points may be? I did mark a couple of spots that may work? I am thinking one high & one lower may be best but not sure where exactly to tap in.
     

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  2. Delmer

    Delmer Senior Member

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    The best way is a core plug block heater if you can find a suitable low core plug that works.
    something like this:
    https://www.jegs.com/p/JEGS/JEGS-Freeze-Plug-Core-Plug-Block-Heaters/752718/10002/-1

    I don't know which core plug would work for you, so you either need to wait for somebody who does, find it somewhere else, or take your chances that there's clearance for the heating element. I've never used the Jegs heaters, and never seen block heaters with 1,500 watts either, usually you only get 400-600W.

    If you use a tank type circulating heater, the heater has to be below the connection with the top hose sloping up to the connection to the engine. At least the cold coolant from the engine has to come from low on the engine, the heated coolant can go to the head or just an inch away from the cold hook up on the block, even the same port if you have a 1" or bigger port. The heated coolant doesn't matter, it will circulate up on it's own. The hoses can't trap air either, they have to slope up to the engine to burp.

    Maybe this will help:
    https://www.heavyequipmentforums.co...e-in-the-heck-does-the-block-heater-go.47898/

    If I understood that right, use the heater hoses to tie in a tank heater, that might be what you have marked in the pic.
     
    Last edited: Nov 8, 2018
  3. kshansen

    kshansen Senior Member

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    Does this machine have an transmission oil cooler? Can't see as it would be to the right of the engine oil filter in the first image. Or is there a 3/4 inch pipe plug in the water elbow that you can just see behind the two 1 1/2 pipes way to the right of the picture?
     
  4. Metalman 55

    Metalman 55 Senior Member

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    I am not sure about the cooler, but now that you mention it, sure looks like there is one cause what else would that large diam line be above the oil filter? I will try to take the cover off tomorrow & get some more pictures of that area.
     
  5. kshansen

    kshansen Senior Member

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    Just to be clean in the picture below the red "X" is on the engine oil cooler. Now it is hard to see what the two lines with the red "Y" go to but if it is a bigger cooler that more or less stands on end that may be the transmission cooler.

    I know this is a D330 but on the loaders that had the 3306 engines the cooler arraignment very much like what this one is and the transmission coolers often had a 3/4 inch plug down at the lower end in the cover where a screw in block heater could be installed. Others had a plug in the elbow that connected the engine oil cooler water to the transmission cooler in the same area as the red "Y". 941 cooler.jpg

    Not 100% sure but where you have the black "X" that is above my red "X" I'm thinking that is in to the air passage for the head and not a water jacket plug. I could be wrong as I have not touched a D330 or 3306 engine in several years!
     
  6. Metalman 55

    Metalman 55 Senior Member

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    I am thinking you are correct in saying the black "x" above your red one is air, as if you look to the right you see the flange coming down from the air filter.

    Weather permitting, I will pull the cover off tomorrow for better pics.
     
  7. Metalman 55

    Metalman 55 Senior Member

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    I went back out there this morning & if you look where the screw driver tip is pointed there is a plug, coming off one of the transmission cooler lines. That is likely a good lower tap in point. On the other pic likely the LH black "X" could complete the loop?
     

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  8. Metalman 55

    Metalman 55 Senior Member

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    Think this will work ok, with that much difference in height?
     

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  9. kshansen

    kshansen Senior Member

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    Only real way to know is to hook it up and fill with coolant and plug it in. Heat rises so the line from near the engine oil filter would be the inlet to the heater and the line near the thermostat housing would be the outlet from heater.

    Remember you don't need to get the engine up to operation temps, just warm enough to start like on a nice fall day!
     
  10. Delmer

    Delmer Senior Member

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    Yes, that should work fine. I'd want to be sure you have a thermostat in that housing, and maybe drain a little antifreeze so the level is just below the radiator inlet so it won't thermosiphon during the winter. Check the temp of the top of the hose after you have it hooked up and running for a couple hours on a cold day, you don't want the hose or radiator top to be warm, that's losing your heat.

    The height difference is what makes it circulate. This link courtesy of TCTractors says you want to MINIMIZE the length of hose, but their diagrams show exactly what you're doing.

    https://www.preheat.co.uk/wp-conten...Mounted_Coolant_Heater_Installation_Notes.pdf

    just like Kshansen said, the top of your heater will connect to the top point, and the side of the heater will connect to the side point, as long as the air can circulate out to the radiator, then it should work perfectly.
     
  11. Metalman 55

    Metalman 55 Senior Member

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    Got it all hooked up. The engine head warmed up nicely after it was running for a short time. Will check the top of the rad hose when I plug it in next time.....hopefully that stays cold. Good suggestion. thanks
     

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  12. kshansen

    kshansen Senior Member

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    As long as there is a good thermostat in the head I don't think it should be a problem!

    I would be more interested to know if the water passage from the engine oil cooler to the transmission cooler get warm to the touch. That would indicate to me there is some circulation going on.

    Not sure if the tank type heater is as sensitive as the in block heater but I would not start or run engine while heater is plugged in. Some times there are some air bubbles in the coolant flow that can let the heating element over heat and burn out.
     
  13. Metalman 55

    Metalman 55 Senior Member

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    I plugged the loader in today so I could move it to work on the track rollers & reaching in the engine compartment found the head to be nice & warm after about an hour, so it seems to circulate well. Side panels were on so I could not reach down to the trans cooler to check it.
     
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  14. kshansen

    kshansen Senior Member

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    Sounds like one in the win column for you.

    Now for a suggestion, I might be looking for some split loom to go around those hoses to give them some protection.

    https://www.mcmaster.com/split-looms
     
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