JD Model A Radiator Reassembly How-to

1939 Model A Radiator Muffler Replacement how-to. This video shows the installation of the radiator, muffler, air stack, and re-assembly of the tractor. As a note–I should have filled the radiator after I re-attached the hoses on the cooling system. I had a leak in one of the hoses, and having the hood off would have made it much easier to adjust. Know that I am not a professional, and you may do things differently or in a different order. I only provided this video for people like myself, as this video would have made it easier for me back when I knew nothing about how to get the hood off and work on the tractor.  Click “read more” for more information.


The installation and reassembly of a classic two-cylinder John Deere tractor is quite simple.  Although it varies from model to model, the basics are close enough that you should be able to follow it with your own model.  Also note that this applies to “styled” tractors, and not unstyled.

To start off, we set the radiator in place on the frame.  The 39 is a little unique, as it is still basically an unstyled tractor but had the styled sheet metal (the frame and motor were identical to an unstyled A).  However, the radiator and everything that connects to it is unique to the 39.  The 39 is a special tractor where it is a unique hybrid of everything less then 39 and greater then 39.

Because of the unique exhaust mount (the muffler is one piece which mounts to the radiator, unlike the latter years), we mounted it before we bolted the radiator down.  That way we could lift it over the exhaust pipe and didn’t have to unhook that too.  Once the exhaust pipe was secured into place in the bottom of the muffler, we bolted down the radiator.

Once the radiator was bolted down, we then attached the hoses for the cooling system.  I learned something in this reassembly though—after you secure your hoses, fill your system with coolant.  I waited till after the hood was in place.  One of my clamps was leaking, which made it very difficult to adjust since the hood is in place.  Next time I will fill it first while I still have complete and easy access to all the hose clamps.  Doing this can save you a lot of work.

With everything bolted down and the hoses all connected & cooling system filled, you’re now ready to mount the hood and tank.  Using two people, lift it over the muffler and air stack. Gently set it down on the tractor, and secure mounting bracket, which sits just in front of the dash.  You then need to install the front grills, as the bolts that go through the grill are the same bolts that hold the front of the hood securely to the radiator.  At this point you can start securing all bolts that hold the sheet metal and grills on.  Do not mount the nose plate yet.

With the nose plate still removed, reinsert the steering rod through the nose and screw it back into place.  Place the cover over the steering pedestal and secure the bolts.  Attach steering wheel and nut.  At this point your tractor should look like itself again!

Now for the final remaining steps.  Attach the nose plate, and depending on your model attach any rods to the carburetor, etc.  The 39 is a very basic tractor so I only had to reattach the fuel line to the fuel tank.  On my 47 and 49 B this part is a little more involved, as I had more items to attach.

As I mentioned before, your models may be slightly different.  I hope this gives you a good overview as to get you on the right path.

2 responses to “JD Model A Radiator Reassembly How-to”

  1. Hi just wanted to give you a quick heads up and let you know
    a few of the pictures aren’t loading correctly. I’m not sure why but I think its a linking issue.
    I’ve tried it in two different browsers and both show the same results.

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