This old 9U was a local tractor that has been bought, used and sold a few times that I know of. We have had it for about 10 years, put some new valves in it and transferred the tracks and idlers from our older 9U with bad track frames and rollers over to it when we got it and had the head reworked. We were using it around the farm and put this rake on it, Had an old weld repair of one track frame fail and we parked it for the time being.

Time stretched into 3 or so years and we are cleaning up some old pasture/brush/scattered trees this fall, so decided that since it was sitting among 3 other 9U's with plenty of spare parts among them, we would replace the track frame and use it again. That went fine, but in the process we discovered that the "slack in the final drive bearings, was really the sprocket was loose on the hub. So we grabbed a final drive and swapped that out, installed the track frame and idler, installed the tracks and pulled her off.

After pulling it a couple hundred yards, I finally checked the tank for fuel! Sure enough, nothing there. So filled it up, bled it and it started within 10 feet. Drove to the shop and cleaned the pony carburetor including drilling out lead plug and passageway across bottom of bowl. This pony has power now! I had thought it was pretty well worn out before, but now it's going good.

Had a recoil spring bolt broken, so instead of going to the trouble to fix it correctly, we put a pin in the sprocket and backed up until the spring was the correct length and then welded some stops on the track frame to keep it from overtensioning the track. I think some of the later tractors use the spring bolt only to get the spring installed and then the adjustment is backed off until the track frame holds the spring at the correct length, so I am confident this will work and is safe etc.

Last thing before driving out of the shop, I put the hood on, sort of knew that was a bad idea, the tractor had been getting hot pretty fast last time we used it much, but that was pulling a disk. Anyway, the temperature gauge was reading cold (sort of wondered about that). Well, the gauge does NOT work and the tractor rapidly overheats when you do any work with it. So, back to the shop, remove the hood and top of radiator and rod it out.

Here's some pictures of the process........The best thing I could find to use for a rod is the stainless steel strips from a windshield wiper. We have a minivan with pretty long wipers, just not quite long enough to reach through the core from top to bottom. Ended up silver soldering about 6" onto the far end of one to finish the job.

IT IS IMPORTANT TO BEND AN L ON THE TOP OF YOUR ROD!

Hazard of doing this job..............wringing bolts off in the cast iron radiator tank and frame. Well, it had to be done, tractor was worthless without cleaning the radiator, so just go ahead and wring them off and then get them out later. All but one were in the top tank, so easy to work on those on the workbench. The single one in the side frame was a bit harder, mostly because it was harder to heat the cast piece where it was threaded in. Welded nuts on them, but that didn't heat them enough to break free, so after wringing the nut off two of them, I heated the casting around each one. The came loose pretty easily.

The best technique for cleaning the radiator flues is to have water flowing up through them so you can see which are stopped up and it will flush debris that you dislodge up and out as you work the rod down through each one. I connected a garden hose to a fitting I found that fit the drain hole in the block. The thermostats kept most of the water from going up the top radiator connection and it worked up through the core just about right. Not so much that it would spray you in the face, but enough to clear the crud out.

In hindsight it would have been better to use the drain in the lower pipe connecting radiator to engine. I think it is threaded so should be able to find something to screw in it or jam in there. There is really not much pressure on this connection.

Got the radiator buttoned up and filled it with plain water to check for leaks.

Everything looked dry, so put radiator guard on and then noticed the water level had gone down. Well, no big deal, had some trapped air, probably...........so filled it back up.

Actually could see it going down!

Everything I could see still dry except for a tiny trickle at a gasket below the generator mount.

Tightened the bolts and increased the trickle. Couldn't think of any water passage there, but CAT did make a D318 marine, with raw water pumps etc, so maybe there's a passage in there that's normally blocked by the generator mount housing?????

Took out a bolt and got a stream of water!

That's when I pulled the dipstick and got a geyser of water out of it too.

OK, when I started the is project, I had an engine that would oveheat, but I drained about 8 gallons of coolant (that I caught in a pail), probably lost a gallon or two, so I'm pretty sure this is a new problem which has arisen after flushing and rodding out the radiator.

I believe when I put a hose on the block drain fitting and flushed back through the block and up through the radiator flues, I must have dislodged a bunch of rust and sediment that was covering the lower sleeve area with old deteriorated o-rings. So now I have a fast leak straight into the pan.

My conventional alternatives are not attractive, I've got a good spare engine (supposed to be a good engine when I bought it) just no time to put it in. I could also pull it down and at least re-seal the sleeves, hone them and put new rings and head gasket set in it. Again, time is against that option. Really need to run this thing this next week, or at least not be working on it, so I can do other things. This would also most likely be most easily done by pulling the engine and working on it out of the tractor, so why not put in the replacement and be done with it?

So, does anyone have any experience with using a sealer for badly leaking o-rings at the bottom of the sleeves? I have used Bars Leaks and also one called Dike which is more of a gel. I was thinking about injecting something directly into the block drain fitting where (most likely) the leak is nearby. Or maybe pouring some down the temperature gauge opening in the head.

My problem is that I can't run the engine until the leak is stopped, so the usual method of adding the magic potion to the radiator, just won't work. It'll have to get where it's needed by gravity, set up and hold well enough that it's not washed away by the circulation of coolant, thereby ruining the oil, bearings etc.

That's got to be a big hole. I think I'd pull the drain plug out of the pan, fill her up and watch the coolant level in the radiator. If she goes all the way down you know you're screwed. If not, maybe you got lucky and its head related.

Other than pulling the drain plug and using a pump to circulate water and your choice of stop leak through the block I can't think of anything else that will work. The problem is I don't think any form of stop leak is going to plug your hole. I always get to wondering if this is going to happen to me when I drain the coolant and don't get it refilled for a few months as liner seals will sometimes leak once they've dried out.

With all your wisdom you know what medicine you should take.
Thats a tuff one to seal any thing you use will leak into the pan. Maybe a hand full of clay mixed with rust flakes and water .

"Tim wrote:

With all your wisdom you know what medicine you should take.
Thats a tuff one to seal any thing you use will leak into the pan. Maybe a hand full of clay mixed with rust flakes and water .

I'm thinking more like hydraulic cement if the hole isn't in the side of the liner.

Success! Have been using the tractor this week and it's pushing great, staying cool and most of all, the coolant is staying in the radiator!

I mixed a couple of pint bottles of Dike stop-leak with a couple quarts of used coolant I had drained from the engine before I started this project. Added this through the block drain hole and let it sit overnight. The next morning I filled the radiator with clean water, drained all the water I could get out of the oil pan and started it up. It seemed to go down a little bit and the oil did get milky, but not too severely, so I kept on running it for an hour working it some pushing the root rake through some old brush piles. The next morning, I drained the oil and refilled with Delo 400 15w40. Never have seen any sign that any additonal coolant got into it and haven't had to add any coolant until today when the temperature gauge got up in the middle of the green for the first time and some would excape from the radiator top when I was on a slope. We added a jug of antifreeze to it and ran it the rest of the day.

I am not sure the gauge is reading high enough, it is a used gauge from another engine here, but seemed to be working this summer when we were using that one. It did seem to boil a time or two with the gauge reading in the middle of the green band, so probably it's not quite right. Tractor was really working piling brush and daytime temperature was up in the mid 70's Farenheight for the first time this week.

With the 9U piling and raking, the D7 can mainly push the trees and then fill the stump hole and move on to the next. Lots more productive than working alone.

Bumping this to make it easy to find 3/22/2020

"ccjersey" wrote:

Bumping this to make it easy to find 3/22/2020

Thanks, I re-read your story and got to enjoy it again.

Jim, is the machine still working 8 years later? U know i got some old original cummins and cat engines and cross my toes every time i start em. Would/could dike or similar be a preventative measure concerning the HORROR of 70/80 year old liner seal failure? Everyones thought please.