Coolant leaking John Deere 4320 4520 4720 compact tractor

[oldtimer 66]

Back to the " L shaped " gasket and shim. I did some calculations on the coefficient of expansion between the cast iron block and cylinder head versus the aluminum FEC. At a 150 deg. F differential the FEC moves .017 more than the cast iron block and cylinder head. I used 60 deg. as a starting temp and 210 deg. F as operating temperature. Roughly measuring the cover is approx. 18" long, that is it's vertical height. Now when you look at the location of the FEC noting that the bottom flange sets directly on the oil pan ( gasket also ) the FEC is some what pined/ doweled at the lower flanged end. The oil pan itself is a structural member/ heavy cast iron member and not a light weight stamp steel piece. That in it's self cause the majority of the expansion to be in the vertical plane from the oil pan up. There is also a horizontal expansion component. What this says is every time you use your tractor and it gets to operating temperature and then it cools down that " l shaped " gasket is seeing this .017 type of movement. That causes fretting over time and eventually gasket failure. More to follow.

 

[oldtimer 66]

Back to the "L shaped" gasket and shim. If you look at your tractor you will notice that there are no bolts/ fastners on the top end of the FEC where it connects to the cylinder head. One reason is the extreme movement between the 2 assemblies ( .017 ). The second reason is that the cylinder block and the cylinder head are not match milled and serialized. This match milling and serializing adds cost. To get the 2 surfaces in plane you would need to completely machine the cylinder block and leave finish material on the forward face. The same would be true of the cylinder head. Then both components would then need to be cleaned, assembled, finish milled to make both surfaces in plane , serialize, dis-assembled, and cleaned again. This is added cost but probably the right way to do this knowing that this design is going to leak. Sunnyside360 trust me, this bad boy is going to leak. Another tidbit is the instructions for the engine leak kit. It says to measure the gap between the FEC and the cylinder head. I will need to pre-assemble the FEC to this. If it is between this and this it is OK but if it is out side this dimension you need to install the shim. Now we just added another part to this assembly and created another surface that can leak. More to follow, I just cant make this stuff up.

 

[sunnyside360]

Sunnyside360 trust me, this bad boy is going to leak.

oldtimer 66, following your posts with interest knowing there has been a coolant leak issue like you described with some 4x20 tractor owners. I could be wrong, but I don't think it has been a wide spread problem judging by the number of complaints on tractor forums.

 

[arlen4720]

oldtimer 66, following your posts with interest knowing there has been a coolant leak issue like you described with some 4x20 tractor owners. I could be wrong, but I don't think it has been a wide spread problem judging by the number of complaints on tractor forums.

I agree with this, considering also that same block was used in many skidsteers, generators, compressors, and other stationary power equipment.

 

[oldtimer 66]

My tractor is a 2006 model, now with approx 1240 hrs. The FEC and water pump were sealed with sealant only. If there were no problems and or minimum issues why would JD add the gasket for the FEC and add a gasket for the water pump and also machine the water pump mounting surface. Sounds like to me that they are trying to correct several problems. Otherwise why would they add this extra costs for two gaskets and extra machining. There are 4 red "X" 's in this design and this is there order of importance #1The cast aluminum cover, it should have been a cast iron/ maybe a ductile iron, to minimize the difference in expansion rates with the cast iron cylinder block and cylinder head, #2 no match milling of the cylinder block and cylinder head, because of that the FEC cannot be clamped to the cylinder head at the L shaped gasket area, the surfaces are not in plane. This is the area on my engine that leaks the most right now. #3 the cast surface for the water pump mounting, utterly ignorant from an engineering stand point, the CFO must have had something to do with that. #4 The upper radiator hose connection,riser and feeder, in a critical seal area. Let's leave it to the last person in the casting shop with the 7 inch vertical grinder to impart some quality into this part. It not his fault. It is the engineer that approved the mold design and the quality engineer that does understand what makes a good sealing surface. I have ordered the mystical/ magical gasket/ Engine leak kit and I will pick it up tomorrow. I also ordered some of the tooling. As I said before my game plan is to fix this bad boy some time in the early spring. I will take pictures and post them for who ever is interested on the repair.

 

[AKfish]

Whoa... I did not appreciate the extent of this problem! Remove the cab, remove the front axle assembly... Good grief! This is not a simple, weekend fix!

I am (and no doubt many others) looking forward to seeing the pictures and narrative of your repair job.

Thanks.

AKfish

 

[oldtimer 66]

To all I will get the list of applications for this "Engine Leak Kit " There is at least one 5000 series tractor and one or two skid steers. Now these kits are only for, I think, the common rail EFI applications on the 4 and 5 cylinder engines. Now I would assume the rotary pump application will have a different engine leak kit. But I have been wrong before. I did pick up the my Engine Leak Kit and I was some what surprised that the FEC gasket is steel / SS/ and it mics .020" thick. Wow what a guess. There is no sealant. It appears to be a stamped pc versus a laser cut. It has as a stippling to match the FEC road map. It is also embossed around each bolt hole and the stippling is approx. .100 wide and proud by about .020" in a V shape that is slightly crowned. It must be a semi magnetic stainless steel and it has a dark gray/ to black coating of a couple of mills. That's my best guess. It reminds me of maybe an mid 60's intake gasket. The shim for the L shaped gasket is aluminum and is only .010" thick and it has been anodized an off yellow? The tabs that locate it to the inside the coolant port are extremely small wow! Maybe .060" X .060" at best. If the new FEC gasket is .020" why wouldn't the shim for the L gasket be the same? Just a dumb question. Another thought would be to make the L shaped that much thicker .020 ". Again another dumb question. The L shaped gasket itself has what I call a single lip seal. I would think now with this re-design you would want to go with a double lip and or maybe even a triple lip. It's like the Great Wall in China. There is just not Wall but I have read that there were as many as 17 Walls in certain areas. This re-design was the time to do this. Too late now. What the L shaped gasket is made of, I do not know. What I do know is that Viton likes water and it swells up in it's present. I have seen it used in one difficult engine application that was prone to leaking. I have info to get everybody and if I have time I will get some pictures of the gasket kit. Later.

 

[oldtimer 66]

The Title of the instruction to repair my tractor is called "Engine Leak Repairs" ? John Deere Installation Instructions RE547689. The instruction is for a compact loader and it also is the instruction for the 4000 series 20 tractors. Now this leak kit is for Tractors 4320, 4520, 4720, 5225, 5325, Compact Loader 304J and 244J. Like I said before this addresses the 2.44 and 3.0 liter engine with common rail EFI. There must be kits for engines without common rail. So to me this is really not a small problem. If you park your tractor in an out building with a dirt and or gravel floor you may never notice this leak. My tractor has always been parked in a heated garage/ concrete floor/ and the leak is very evident. If I get a part number for the other leak kits I will forward. Later.

 

[sunnyside360]

If you park your tractor in an out building with a dirt and or gravel floor you may never notice this leak. My tractor has always been parked in a heated garage/ concrete floor/ and the leak is very evident.

Good point especially for very small leaks. Low coolant in the reservoir should eventually show up a problem. My 2010 4320 is parked in an unheated building with a concrete floor and so far no FEC coolant leak. Got my fingers crossed and continue to follow your work/analysis with utmost interest.

 

[sunnyside360]

The Title of the instruction to repair my tractor is called "Engine Leak Repairs" ? John Deere Installation Instructions RE547689. The instruction is for a compact loader and it also is the instruction for the 4000 series 20 tractors. Now this leak kit is for Tractors 4320, 4520, 4720, 5225, 5325, Compact Loader 304J and 244J. Like I said before this addresses the 2.44 and 3.0 liter engine with common rail EFI.

John Deere made some changes around 2009 on the 4X20 series tractors. Does this leak repair kit call out serial numbers and/or model years?