Did you have to pull the radiator and what tech manual do you have. I have the same coolant leak also.
4320 Coolant Leak from Timing Cover advise please
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oldtimer 66
Platinum Member
Yes, I pulled the radiator but i left the oil cooler and AC condenser? attached. I purchased the maintenance CD when I bought the tractor. The manual or one of the writeup's says to remove the engine i think. I can't remember. I just supported the front of the tractor on the 2 spindles for the loader frame. A previous question on the 2 bolts from the back side of the bellhousing. You need to remove them to get the oil pan off.
oldtimer 66
Platinum Member
Rob REESE, look at brad5541 pictures. He has the tractor supported just like I did and he removed the radiator like i did.
I think I may have recently had this issue on my 2005 model 4120. I noted that the coolant level was approx 1/2 gallon low a couple months ago and I topped it off then. About a week ago, the high temp alert came on and again it was about 1/2 gallon low on coolant.
I had last changed the coolant 14 months prior, using JD coolant at the recommended water mix ratio. Not having the time to pull the front axle and the oil pan, or spare $6 k around to do the job “properly” at the dealer (I assume that would be the approximate cost of the job now since everything has doubled in cost since Covid), I opted to pour a $ 16 bottle of K-seal into the radiator.
It’s only been a few days, but I’ve been working that tractor pretty hard getting ground ready for and planting corn. So far the $16 fix is working. It says on the bottle that stuff makes a “permanent fix”. Time will tell I guess. The coolant level is holding after about 10 operating hours.
I had last changed the coolant 14 months prior, using JD coolant at the recommended water mix ratio. Not having the time to pull the front axle and the oil pan, or spare $6 k around to do the job “properly” at the dealer (I assume that would be the approximate cost of the job now since everything has doubled in cost since Covid), I opted to pour a $ 16 bottle of K-seal into the radiator.
It’s only been a few days, but I’ve been working that tractor pretty hard getting ground ready for and planting corn. So far the $16 fix is working. It says on the bottle that stuff makes a “permanent fix”. Time will tell I guess. The coolant level is holding after about 10 operating hours.
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I also have a 4320 that leaks from the front cover. I believe when they assembled the motor they used RTV instead of a gasket. I think I will try your fix before I take it to a dealer. It is an extensive job to fix it and I wouldn’t doubt that the dealer would just use RTV again.
What year is yours ? It sounds like the dealer “fix” has been to replace the sealant with a gasket. It sounds like once that’s done, there hasn’t been any reoccurrences. Only trouble is coming up with the $ 6k to cover the 20 hours of dealer time to do the work. It sounds like lots were covered under warranty. They did come and get my tractor, to do something on it when it was less than a year old, but I’m not sure what that was.
I’m not certain the K-seal will make a permanent fix however it has some pretty good reviews on-line, and sounds like it is particularly effective on leaking gaskets. It also has no known “bad” effects like plugging up thermostats, etc.
How often have you been refilling your cooling system and how much have you usually had to add ?
I’ve known about this issue for many years but only experienced it over the last few months on my 2005 model 4120 tractor. I’ve changed my coolant several times over the years, to try and minimize the chances of trouble. I’m hoping the K-seal really is a permanent fix.
I’ve had decent luck with at least one other “magic chemical” fix, that being “Slime” in my lawnmower and field car tires.
I’m guessing the coolant leak problem didn’t show up on my tractor for 19 years because it was one of the early ones made back when the casting patterns were relatively new. Later ones probably had issues with porosity and non-uniform wall thickness, after those patterns wore down a little. Also, mine is the base model at 43 engine hp. The “tuned up” others: 4320, 4520, and 4720 likely run hotter and at higher pressure.
One thing we will never see is a tractor mechanic or dealer recommending a “chemical” fix. I guess you can’t blame them for that, because they need to earn a living too.
Mine is a 2009 4320. Mine doesn’t leak as bad as yours yet but I am afraid it will get worse. It leaks a couple ounces a week. There was another thread on here with another guy who had the same issue and he actually fixed it himself by disassembling the tractor. It was quite extensive. You have to remove the radiator, the front axle assembly and then you have to drop the oil pan before you can remove the front cover. I thought about trying it myself but I don’t know. The guy had pictures also.
Mine hadn’t leaked any until about a month ago. I just checked it tonight and the K-seal is definitely holding so far. I haven’t really got into the heavy usage yet this year for that tractor though. I bush-hog about 30 acres with it, usually in the hottest part of the summer. That will be a good test for it.
I’ll work it pretty good tomorrow too, hauling dirt with the loader. My only other 3 point tractor (1951 Ford 8n) is down right now with a no spark issue, so the JD 4120 has got to do a little extra work.
Probably to save money and/or time but more likely somebody just didn’t know no better. Happens everyday, old knowledgeable folks retire and those that replace them are lacking know-how. Not taking into account the fact that different materials (in this case iron and aluminum) have different thermal expansion coefficients is a classic “rookie mistake”.
One with more knowledge would have used a gasket rather than a sealant here, because a gasket can continue to expand to fill the varying thermal expansion gap, for a lot longer than a sealant can in most cases. That’s why none of us has heard of repeat of the problem after the sealant was replaced with the gasket (hindsight is always 20/20).
That being said, those rookies more often than not bring in new ideas and improvements that push the performance beyond what was achieved by the older folks.
I’ve been pretty impressed by the overall performance of this particular engine, going on 20 years now. Only other problem has been the starter, which I had to replace just out of warranty. Luckily, that was cheap and only a 15 minute job. I’m on my third starter now.
There again, the problem was caused by improper material choice, this time for a stud on the original oem Bosch starter. I got 14 years out of the cheap aftermarket replacement but only 3 years out of the original. Most users probably would not have suffered this one but I use my tractor for snow removal in the winter in a part of the country that uses more road salt than almost anywhere else.
I’m certainly hoping that the K-seal does the trick this time. I’ll be on the watch for trouble, and the high temperature alert on the dash panel of this tractor makes it very easy to see when it starts. I did a fair amount of research, when selecting a liquid repair product, and this one came out on top.
My biggest concern was plugging something up and doing more harm than good. There have been almost no complaints of that for K-seal, compared to others like Bars. I had some of that in my shop, but was very reluctant to use it on this tractor.
I certainly don’t have the time, money, or ignorance required, to pull this tractor apart and install a gasket, when a $16 “miracle in a bottle” might fix the problem for good in less than 10 minutes.
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