4320 Coolant Leak from Timing Cover advise please

   / 4320 Coolant Leak from Timing Cover advise please #41  
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.
View attachment 873023
View attachment 873024

I have a 2008 4320 and so far, no issues. I don't put may hours on it, so I hope it lasts without many problems. I did have to rap on the starter the other day to get her fired up.

It appears from the dealer sticker you bought your tractor in Springville. My Dad used to do business with them for many years before they were bought out. I miss the old mom and pop dealers. I remember they also sold Kawasaki and Hodaka motorcycles.

Dave
 
   / 4320 Coolant Leak from Timing Cover advise please #42  
I have a 2008 4320 and so far, no issues. I don't put may hours on it, so I hope it lasts without many problems. I did have to rap on the starter the other day to get her fired up.

It appears from the dealer sticker you bought your tractor in Springville. My Dad used to do business with them for many years before they were bought out. I miss the old mom and pop dealers. I remember they also sold Kawasaki and Hodaka motorcycles.

Dave
That was a bit of a drive for me, way down near the south border of the county, while I’m up on the north end. They were running a special at the county fair the year I bought that tractor.

There was another “mom and pop” JD dealer, just a few miles from our place up north, but they just got bought out last year also. At least it’s still a handy place to pick up my oil and air filters (that’s all I’ve been to the dealer for), and the same friendly and knowledgeable guy still works the parts counter.

He struggles a bit with the fuel filter though. I’m still running the original on my tractor (from 2005). I’ve asked for one, the last few years, but they’ve never had it in stock. I usually add a little “performance additive” to my diesel with each fillup and have not had any fuel delivery issues after 1250 hours of operation, or any water to drain.

Our local dealer handles mostly lawn tractors, but I see they have a used 4720 compact for sale on the lot up there now, and it looks like there are some new compacts out on the lot. Still no larger ag tractors though.
 
Last edited:
   / 4320 Coolant Leak from Timing Cover advise please #43  
I have a 2008 4320 and so far, no issues. I don't put may hours on it, so I hope it lasts without many problems. I did have to rap on the starter the other day to get her fired up.

It appears from the dealer sticker you bought your tractor in Springville. My Dad used to do business with them for many years before they were bought out. I miss the old mom and pop dealers. I remember they also sold Kawasaki and Hodaka motorcycles.

Dave

Way back early in my career we had a front line fire engine that had a ball peen hammer chained to the truck to whack the starter. It also had a trickling water hose to keep the leaking tank full, and an air hose to keep the brakes charged with air.
 
   / 4320 Coolant Leak from Timing Cover advise please #44  
I was going to relax today after a pretty busy “vacation day” yesterday, but I managed to get 4 more operating hours on the 4120 this morning. Most of that was heavy duty bush-hogging. I also cut up and hauled up a large ash tree that fell into one of our hay fields over the winter.

Still no signs signs of coolant loss or excessive temperature rise so I think I may be out of the woods with my 2 minute, $ 16 K-seal cooling system repair.
IMG_4600.jpeg

IMG_4601.jpeg
 
Last edited:
   / 4320 Coolant Leak from Timing Cover advise please #45  
I have a 2008 4320 and so far, no issues. I don't put may hours on it, so I hope it lasts without many problems. I did have to rap on the starter the other day to get her fired up.

It appears from the dealer sticker you bought your tractor in Springville. My Dad used to do business with them for many years before they were bought out. I miss the old mom and pop dealers. I remember they also sold Kawasaki and Hodaka motorcycles.

Dave
If your starter keeps giving you trouble, the repair is cheap, quick and easy. I got an aftermarket replacement starter from Amazon last fall for around $ 140. There’s just two bolts and one electrical connection so changing it out was an easy, 15 minute job.

I’m not sure how long this new one will last me, but I only got (3) years out of the oem Bosch starter. The first aftermarket replacement (PowerStrike) lasted about 12 years with no trouble but started loosing strength over the last couple years.

That caused me to replace my battery a couple times unnecessarily. I put the “castoffs” to good use including replacing the original backup battery on my year 2000 “camper special” Chevy Silverado pickup. The amp gauge was flickering on that truck when it had the 20 year old 2nd battery in it. That went away when I changed it out with the NAPA Legend replacement that I had bought for my 4120. It fit the truck because it had both top and side (GM) style posts.

I used the other one (a 6 year old Exide with just top posts) to replace a 12 year old battery that had been struggling for a few years on my dad’s JD 770. I have a pretty good supply of ancient batteries around here that I turn in for core exchange so that I can “repurpose” those that may still have some life in them.

One thing they have improved on greatly, over the last 70 years, is ease of maintenance. That John Deere 4120 is a joy to work on compared to my Ford 8n. To change the oil filter on that old Ford, I got to remover the fuel line and rotate the fuel shutoff/bulb/filter. I’m really not looking forward to pulling the hood and fuel tank off of it so that I can change out the wire harness.

A good rainy day project I suppose, and no rush now that my JD 4120 seems to be back up to 100 % since the $ 16, 2 minute “miracle in a bottle” K-seal cooling system repair.
 
   / 4320 Coolant Leak from Timing Cover advise please #46  
(4) more operating hours this evening, last 15 minutes with the lights, all heavy bush-hogging. This was our warmest day of the year so far at 85 F. The engine temperature gauge stayed well in the green throughout. I’ll check the coolant level again, prior to next job, but I doubt it lost any.
 
   / 4320 Coolant Leak from Timing Cover advise please #47  
I noticed my coolant temperature starting to creep up a little closer to the red zone on the gauge, as I was getting near the end of bush/hogging this thick, 5 acre hay field on Tuesday night. I was wondering if the coolant leak might have started again.


I used the 4120 tonight, to move some firewood, and I discovered what caused the slightly higher than normal temperature. Cotton, from the poplar trees growing along the creek across the back of the field, had built up about an inch thick over the entire grill.

Now I feel safe to move my jug of 50/50 coolant mix back up to my long term stage shelf in the metal shop. I had been keeping it in the back tractor shed where I keep the 4120.

IMG_4612.jpeg

IMG_4611.jpeg
 
   / 4320 Coolant Leak from Timing Cover advise please #48  
I noticed my coolant temperature starting to creep up a little closer to the red zone on the gauge, as I was getting near the end of bush/hogging this thick, 5 acre hay field on Tuesday night. I was wondering if the coolant leak might have started again.


I used the 4120 tonight, to move some firewood, and I discovered what caused the slightly higher than normal temperature. Cotton, from the poplar trees growing along the creek across the back of the field, had built up about an inch thick over the entire grill.

Now I feel safe to move my jug of 50/50 coolant mix back up to my long term stage shelf in the metal shop. I had been keeping it in the back tractor shed where I keep the 4120.

View attachment 874209
View attachment 874210
Same exact thing happened to my Kubota BX. The radiator screens won't stop the small stuff.
 
   / 4320 Coolant Leak from Timing Cover advise please #49  
I took a vacation day from my factory job today, and I pulled a “David Frizell” with the 4120 (That’s 10 more operating hours). I started out cultivating and spraying my first planting of field corn. It was up about 2 ft and looking pretty weedy.

Next, I hauled a bunch of top soil and finish graded around a barn demolition site, next to my pole barn. I ended with a few more hours of heavy brush-hogging. We are just getting into a heat wave and the air temperature was in the mid to upper 80’s most of the time.

The K-seal coolant system repair continues to hold. Even though my grill was about 3/4 blocked by Timothy seed by the end, the coolant temperature stayed well within the green the whole time.
IMG_4670.jpeg


IMG_4673.jpeg
 
   / 4320 Coolant Leak from Timing Cover advise please #50  
I’m now about half way thru one of the biggest jobs that I do every year with my 4120 (bush hogging about 20 acres of hay fields). The K-seal continues to hold. In fact, my coolant temperature has been running as cool as I’ve ever noticed it during that job.

It will be interesting to see how long this repair lasts (it said that it’s permanent on the bottle). I’ll continue to change the coolant every 10 years or so and see how I make out.

I finished up the 3rd field yesterday after work, and there’s (3) more to go. I’d like to get back on it today but it’s raining pretty hard. I wouldn’t mind cutting in a light rain because my canopy would keep my dry and that would keep the dust down.
IMG_4715.jpeg

IMG_4716.jpeg


I also hauled up and processed a small dead ash tree, that had fallen onto one of the fields. My old Ford 8n is broken down so the John Deere 4120 is needing to do most of the work around here now.

My favorite part about owning a Ford and a Farmall tractor is the appreciation they give me for mostly running John Deere tractors.
 

Tractor & Equipment Auctions

500 Gal Fuel Tank (A44502)
500 Gal Fuel Tank...
John Deere 1023E (A44501)
John Deere 1023E...
2017 GMC Sierra Pickup Truck, VIN # 1GTR1MEC6HZ115515 (A44391)
2017 GMC Sierra...
New/Unused 2025 STSD10 Seeder (A44391)
New/Unused 2025...
2007 Diamond C Gooseneck (A44502)
2007 Diamond C...
Scag Z Cat (A44502)
Scag Z Cat (A44502)
 
Top