L1801 coolant leak from weep hole

[celkins]

Hello and thanks to everyone for their very informative posts about Kubota tractors and their gray market counterparts.

I just finished a full engine rebuild of my L1801 and thankfully the rebuild was mostly a success, since it does crank and run.

I am having an issue of coolant leaking from what appears to be a weep hole in the front cover, just below where the top coolant pipe is attached to the block. I do know there is NOT a hole in the block where this hole is located in the front cover. This hole is only in the timing gear cover and front water jacket cover.

Has anyone else has had a similar issue? Can anyone give some insight to what's going on? The leak isn't pouring out. It's just a drip....I'd say a drip every 2-3 seconds.

I'll try and get a photo of it leaking in the next day or so.

Thanks for your help,
celkins


Here's a link to another site with someone having the same issue. I don't see that they ever found the cause and I have yet to get a response from that post.

Kubota L185 coolant leak (plug pin?)

I have a buddy that s nearing completion rebuilding an L185 Kubota engine. He got everything back together and has coolant pouring out of a hole in the front. This is his first rebuild and I m trying to help him, but have no experience with Kubota engines. After looking at "rough expanded parts...

www.yesterdaystractors.com

 

[dfixit1]

I’m not familiar with your engine but looking at your pictures I suspect you are leaking coolant internally at the water pipe to the hole.
what type of seal did you use?
was the block mating surface clean or did it have any pits?
(see my arrow in pic, coolant leaking from there to hole)

 

[whitetiger]

Hello and thanks to everyone for their very informative posts about Kubota tractors and their gray market counterparts.

I just finished a full engine rebuild of my L1801 and thankfully the rebuild was mostly a success, since it does crank and run.

I am having an issue of coolant leaking from what appears to be a weep hole in the front cover, just below where the top coolant pipe is attached to the block. I do know there is NOT a hole in the block where this hole is located in the front cover. This hole is only in the timing gear cover and front water jacket cover.

Has anyone else has had a similar issue? Can anyone give some insight to what's going on? The leak isn't pouring out. It's just a drip....I'd say a drip every 2-3 seconds.

I'll try and get a photo of it leaking in the next day or so.

Thanks for your help,
celkins


Here's a link to another site with someone having the same issue. I don't see that they ever found the cause and I have yet to get a response from that post.

Kubota L185 coolant leak (plug pin?)

I have a buddy that s nearing completion rebuilding an L185 Kubota engine. He got everything back together and has coolant pouring out of a hole in the front. This is his first rebuild and I m trying to help him, but have no experience with Kubota engines. After looking at "rough expanded parts...

www.yesterdaystractors.com

I am pretty sure that coolant is leaking from the hole rust through the nipple ( right above your red circle in the first pic) and seeping out the hole.

 

[celkins]

I’m not familiar with your engine but looking at your pictures I suspect you are leaking coolant internally at the water pipe to the hole.
what type of seal did you use?
was the block mating surface clean or did it have any pits?
(see my arrow in pic, coolant leaking from there to hole)

Thanks for your reply. I wondered the same thing, suspecting the o-ring I used (which came in the rebuild kit I purchased) was not the correct one for this engine. The gaskets used are grey felt/paper gaskets that came in the kit as well (correct size and configuration). Block mating surfaces were clean with no pitting as you can see from the photo attached to this message. I did use UTV sealant on both sides of these gaskets. There seems to be much deliberation on whether this is a good practice or not, but I chose to use it from experience working on older equipment. It makes for tougher cleanup of surfaces if you have to go back in for another repair but the sealant does make up for minor inconsistencies of mating surfaces, especially aluminum in my experience.

I think I have it figured out but it's hard to explain. I'm going to post a reply later, after I get a new gasket and take some photos, in hopes that it may help someone else.

Thanks again,
Casey

 

[celkins]

I am pretty sure that coolant is leaking from the hole rust through the nipple ( right above your red circle in the first pic) and seeping out the hole.

Thanks for your reply. There is no "rust through hole" in the water nipple. You might be referring to one of the slots in the lip of this nipple but there is not sufficient rusting or pitting of the nipple or block in this area. There was pitting of the lower nipple (not pictured in any of these photos or near this area in any way) which was replaced during the rebuild.

I think I have the situation figured out after some investigation last night. I'll try and post a follow-up to this thread after I get a new gasket, take some photos and put everything back together. Maybe someone will get some use out of it one day.

Thanks again for your reply, Casey

 

[celkins]

Issue RESOLVED!!! See photos and explanation...

I found and repaired the issue. Hopefully this explanation of the problem will help someone in the future, although it is not specifically related to Kubota, Zen-Noh or any other tractors for that matter.

FWIW - The problem I found could happen to anyone servicing equipment that was previously serviced by someone that was careless or ignorant about what they're doing.

This water jacket cover had been R/R prior to me purchasing the tractor. During that process, when cleaning the timing cover mating surface for the water jacket cover, someone cleaned it with what appears to be an air grinder with a scotchbrite pad. You'll see in photos that the mating surface was not flat nor was there sufficient material to sandwich a gasket between in spots. That is where the leak came from. Photos "cover 1b" & "cover 1c" show this in the smaller bottom hole. Even though I used UTV sealant, it was not enough to compensate for the 'washed out' nature of the mating surface.

Once I had cleaned the entire mating surface it became evident what had happened. This was a complete oversight on my part when cleaning and putting everything back together the first time. I'm not sure I would have thought to try and repair it at that point, but my new experience should help me in the future.

After much thought I decided to try and repair this mating surface with JB Weld. I'm not a fan of using it but in this instance, and short of purchasing a new timing cover and all that entails, I decided to give it a try. After applying it and letting it dry I sanded flat and smooth with files and emory cloth to match the rest of the water jacket mating surface.

After reinstalling the cover, checking for leaks, putting everything back together and running for approximately 45 minutes...no leaks.....YAYYYY. I'll be re-torquing the head bolts tonight and putting the loader back on later this week.

The JB Weld did the trick this time. There are no stress areas in this application so I'm really not worried about it failing in that regard. If, for some reason, it fails to hold to the aluminum timing cover inside the water jacket cover I'll just have to cross that bridge when I get there. On the plus side - if it does fail there is no water pump for bits to get sucked into and break....and the worse that'll happen is that it should leak in the same place it did when I noticed it the first time. In that case I'll try and source a timing cover, knowing what the issue is should give me a leg up.

Hopefully this will help someone eventually.

 

[celkins]

First set of photos. Second set to follow...

 

[celkins]

Second, and last, set of photos.


Edited to add tags:
185 175 1800 1801 1500 1501 751 851

 

[rentthis]

I did some investigating in Kubota illustrated parts on similar engines. What I found was that there is a good chance that hole is supposed to have a pin in it. I don't know for what reason. maybe to orient the gasket but it's there on several engines with that set up. If that is the case, you can probably solve you problem by stuffing the hole with JB Weld or a stick.

 

[rentthis]

I checked and the pin is common to 3. The part number is 05012-00408. Messick's has it for 55 cents.

 

[North Idaho Wolfman]

The dreaded aluminum rot...
Good job finding it and fixing it up.
Future permanent repair if needed, would be to pull the case and have the surface machined down to make it flat again.

 

[North Idaho Wolfman]

Rentthis,
I know the pin your talking about, but this model does not have that pin.
That is truly a weep hole.