# YM2000 Radiator Drain



## Hugh Odom (Sep 28, 2019)

Hi, folks. I recently acquired a YM2000 from a friend. I'm gradually working through some minor issues and have a question about the radiator drain.

My friend had installed a new radiator from Hoye a few years ago. When I went to drain the coolant prior to replacing the head gasket, I found a plastic screw in the radiator header near the return hose connection. I tried turning it counter-clockwise and it didn't loosen; turning it clockwise had no effect either. I just pulled the lower hose to drain the system and reinstalled it when I was through. But now I find I have a slow, fairly steady drip of coolant at this nylon screw.

Should there be a drain cock in this location, or is the plastic screw original? I'm sure I can get it out one way or the other; I'm just hoping the threads on the radiator are OK and I want to make sure I can easily replace it before I destroy the screw removing it.

Hugh in SC


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## bmaverick (Feb 20, 2014)

Huge,

Welcome. Can you snap a pix of this plastic screw? They Hoye product should be a good one. Most modern radiators have high temp nylon plastic tanks now days. As for the plastic screw, it could be the actual drain or used for mounting an internal trans cooler. A pix would help tell this story. 

On many of the Yanmar's, there is a drain line to a metal fitting box on the frame. At the base is a drain plug. 

AND to be on the safe side, yours is a true YM2000. Not the YM*G*2000 nor the YM2000B correct? 
This does made a BIG difference.


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## winston (Aug 19, 2008)

Could be this one but I sure don't know. The 2000 parts manual does not shown one like you are describing. https://www.hoyetractor.com/PROD/124060-44510.htm

This is the plug that fits in a 220 which has the kind of drain you are describing. I don't guarantee either will fit. https://www.hoyetractor.com/PROD/DP-110.htm


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## Hugh Odom (Sep 28, 2019)

Here’s a pic of the plastic plug (At the left). I’m guessing it was over-torqued at some point and the plastic threads stripped in the middle of the plug, so turning it won’t tighten or loosen it.


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## bmaverick (Feb 20, 2014)

Not sure if the image is rotated or the hose and plastic screw sit level with the ground. 

Looking at the Hoye exploded parts diagram, I can not seem to locate what is in your pix. 
The hose (45) & it's clamp (46) to the radiator are shown. Yet the other hose (33) to the water-pump is next to these items. 

Does this image resemble your Yanmar?


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## bmaverick (Feb 20, 2014)

I was able to look at 121462-44500 New Radiator for Yanmar Tractor YM Series 1510 1301 1401 1502. The image does show a drain screw of sorts in the very bottom left corner. Wish the image wasn't so blurry when zoning into it.


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## bmaverick (Feb 20, 2014)

Found a good large size image of the YM2000 OE radiator that was re-cord. It's from eBay, but it would not allow a direct link to the image. So, I had to cut-paste here.


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## bmaverick (Feb 20, 2014)

While doing some more digging, I found out that the YM2000 is nearly the twin to the YM240 (US) model. So, maybe your radiator was replaced and a YM240 one is there instead. 

Now, with the plastic screw out, does the hole seem to be metal with threads or is it plastic too? Are you able to take the plastic screw to a hardware store and find the thread size match? Then get a replacement with a backing flat o-ring.


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## Hugh Odom (Sep 28, 2019)

Thanks for that info. The plug is in the same location as shown in the photos you posted. I haven’t gotten the screw out yet; I guess I’ll try gripping it with Vice Grips, pulling, and unscrewing. The radiator is all metal, so hopefully the boss the plug screws into is metal too. I’ll update after a removal attempt.


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## Hugh Odom (Sep 28, 2019)

So...mystery solved. Apparently the drain boss broke off at some point and this was a jury rig repair. The plastic bolt was longer than the depth of the radiator tank. A short section of hose was placed over it to barely keep it from bottoming out. The threads really didn’t grip very well so it couldn’t pull tight enough to seal. The hole is approximately 1/4” in diameter. I’m thinking on how I can repair it. My first thought is home-made rubber repair plug like they sell to fix stripped oil plug drains.


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## winston (Aug 19, 2008)

If you enlarged the hole to 3/8". https://www.lowes.com/pd/Blue-Hawk-...e-Bolt-Drywall-Anchor-Screws-Included/3385762

And this: https://www.lowes.com/pd/Hillman-4-...nc-Plated-Standard-SAE-Fender-Washers/3012351

And this: https://www.ebay.com/i/352758573253...BkX5JBrPohRb0Ep_8RmoF0qDq9n6X5aRoCZa8QAvD_BwE

And this: https://www.amazon.com/Hard-Find-Fastener-014973211851-Washers/dp/B00L1IUQHW?ref_=fsclp_pl_dp_8

Might be easier to take the radiator off and to a shop.


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## bmaverick (Feb 20, 2014)

Hugh Odom said:


> So...mystery solved. Apparently the drain boss broke off at some point and this was a jury rig repair.


Good detective work.

Sort of like Winston's idea, just make the fitting permanent.

Use the 3/8 synthetic rubber washer and then thread in one of these.

https://www.homedepot.com/p/Everbil...ee-Brass-Flare-Union-Fitting-801539/207176766

or

use the washer and a simple brass fitting drain cock. Job done.
https://www.amazon.com/Milton-Compressor-Tank-Drain-Cock/dp/B01M59JKV7

Just find a size that would work in that hole. Even use plumber's tape on the threads too.


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## Hugh Odom (Sep 28, 2019)

There may actually be enough meat there to tap the hole, and I can enlarge if necessary. I’ll try that first and install a suitable drain cock. If that fails, I’ll try the rubber repair plug idea. Something like this:


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## Hugh Odom (Sep 28, 2019)

Well, it turned out there wasn’t enough meat there to hold threads, so I went with a home-made repair plug. Installed, refilled the cooling system and ran it for ~30 minutes; no leaks. Works for me!


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## winston (Aug 19, 2008)

I like it!


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## Qcumber guy (Jun 25, 2017)

On my YM240D there is a bleeder pipe on that nipple as in one of the photos.
It connect just behind the alt to the engine block ( I still don't know why it's needed there!!!)
On the opposite side was a plastic drain valve (heat/age damaged) that I just blocked off with a brass plug and some ptfe tape so can be used still to drain.


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