Komatsu D65e-6 overheat

[southernman13]

Tenfo good luck hope u figure it out!

 

[jasonharville]

After wrestling with the seat frame for several hours I was finally able to get it dislodged and out of the way. I had to use a cable come-along to pull it up and out. The valve cover was fairly easy to remove except for the fact that it was well sealed to the trans. The valve assmbly was also easy to remove. Odd as it sounds, I was pleased to find 2 broken o-rings and a third that appears to be eroded on the underside. Here are pics of the process.

Seat frame removed.



Valve cover removed


Valves removed(broken seals)

 

[mikebramel]

Weird,almost looks like the one on the right went under vacuum

 

[jasonharville]

Weird,almost looks like the one on the right went under vacuum

It does look that way but I think something caused the ring to grow/swell. It is too large for the seat. I lined everything up on the bench and determined that all 3 bad seals were on the forward/reverse ports.

Is anyone familiar with what type off rubber these red orings these are? I have the standard nitrile orings on hand as possible replacements.

 

[GregsHD]

The red o-rings are usually silicone but may have better luck with Viton?

 

[DMiller]

Usually with silicone orings is a stiffener ring of a harder material as plastic or tin, the oring is just a seal. I wonder if had been changed and the extra parts disregarded.

 

[John C.]

I've seen a lot of those glued in. They hold OK unless you get over heating problems. It also might be just a factor of the age of the machine or if anyone has been in there before an put the wrong ring in. If they are on the clutch packs its not likely to be causing an over heat issue. Usually if there was enough leakage the pack would be slipping.

 

[jasonharville]

I ordered some viton replacement o-rings which should be in tomorrow. I am not overly confident that this will fix my overheating issue unless high volumes of oil are escaping between the valve assemblies. Either way it was a needed repair. I also ordered new oil seals for the shift levers. I am pretty sure someone welded on the levers without removing them. The seals look partially melted.

 

[jasonharville]

Usually with silicone orings is a stiffener ring of a harder material as plastic or tin, the oring is just a seal. I wonder if had been changed and the extra parts disregarded.

Based on parts diagrams there is only a single oring for each port. No idea if the silicone rings are original. No sign of RTV on the cover gasket so this may not have been messed with before.

 

[jasonharville]

Between rain and other projects around the house I wasn't able to get the dozer put back together this past weekend. I did go ahead and take a closer look at the area around the steering valve assembly b/c I knew I had some leaks coming from that area that were not easy to reach with the seat frame in place. I yanked the steering valve for inspection and found that most of the o-rings were hard and in need of replacement. But I think most of my leak was originating from loose bolts on the front of the big plate that covers the brake/axle housing. I could move some of them with my fingers. As I tightened them I saw some oil squeeze out of the mating surfaces, so I know fluid must have been passing through it.

At this rate I should probably be buying O-rings in bulk. I think I have most of the leaks on the rear half of the machine corrected now....whether there is improvement in overheating remains to be seen. Hopefully I'll be able to report back later this week.

 

[jasonharville]

Finally got her back together. Zero change on the overheating. There is probably a 15 or 20% improvement in pushing power. It would rarely spin the tracks before but does it readily now. The leaks on top of the Trans valve cover are also fixed. I am probably going to have to run it in short bursts for awhile until this 3 acres is cleared. Then I will go back to the drawing board. I guess pulling the torque converter is my next option but I may try to reconfirm fluid volume to the oil cooler at various temps.

 

[ATCme]

Any updates on the over heating? I'll be heading up to mine in a few weeks to play with and just looking for any input.

I'm also thinking i might have clog in the heat ex changer somewhere. Any work i do to the machine can only be done in the two weeks i'm there. After this it sits until April.

 

[jasonharville]

Any updates on the over heating? I'll be heading up to mine in a few weeks to play with and just looking for any input.

I'm also thinking i might have clog in the heat ex changer somewhere. Any work i do to the machine can only be done in the two weeks i'm there. After this it sits until April.

Hi,

I had a fairly significant turn of events that has left me too frustrated with myself to post any updates. A few months ago I developed a leak in one of the standpipes between the oil cooler and the water manifold. Rather than try to fix the leak, I just put more water in the radiator each time I ran it. The leak got to the point were 4-5 gallons of fluid would go missing between uses. Interestingly, after several rounds of topping off the radiator I noticed that I was able to run the dozer for longer and longer periods of time without over heating. It got to the point where I was running it 2-3 hours without going over 190 and the only reason it seemed to overheat then was b/c enough coolant had leaked out. I theorized that the high volumes of leaking was acting as a coolant flush of sorts. The problem with this is that I think I may have been inadvertently flushing some Stop Leak out of the system at the same time. One day I was cutting some heavy clay for a pond damn and I felt the engine bog, then start screeching. As I went to throttle down and shut it off it screeched to a halt and blew the cap off of the engine oil fill tube. I could immediately see that the oil was gray and sludgy. I'm pretty sure I "unstop leaked" someones previous fix and ended up with lots of coolant in the oil. The engine was stuck until it had time to sit for a few hours. I checked to see if it would turn over and it surprisingly fired right up but only ran for about 5 seconds(sounded ok) before it started screeching again so I shut it down. I'm guessing I lost oil flow to some bearings and will need some significant engine work. I had to rent a Case 750 to get some work done over the last month but I'm probably going to be doing engine investigations soon. I feel like a pretty big idiot for not paying closer attention to the fluids.

 

[Delmer]

Sorry to hear that. It really stinks to have that happen when you had some hope that it was going to be fixed too.

 

[ATCme]

Wow that really sucks.
Sounds like our machines have the identical problems with different engines. I did the head gaskets and rebuilt the heads with new valves on mine back when i first got it. I never even let mine get up to temp before i fixed it so i don't know if it over heated because of it but grey oil usually points to blown head gasket in my experience. Again i was told these hold Cummins have head gasket issues. One can only hope it's that easy.

 

[DMiller]

The old Cummins had block issues, stress cracks in upper counterbores, lack of sealant in upper counterbores led to seepage, head gaskets would erode the top of the blocks just by the engine's firing causing the heads to wiggle, a broken head bolt was common usually the single ones between the heads. Had to closely inspect them each head removal for stress cracking.

 

[oldhousehugger]

With regards to stalling due to fuel issues, on my Komatsu D20, the problem was a clogged in line filter screen in the banjo fitting under the inlet to the lift pump. I cleaned out that little filter under the banjo fitting and installed an inline diesel fuel strainer under the fuel tank that I can visually check. The one I got was similar to a Wix 33972 clear plastic that you can check to see if its time to clean it out. Parker makes one with a fuel bowl and removable element for 10 times the price. Since I put the strainer in I have not had a fuel issue on the dozer again. Same thing with my old 8430 John Deere pulling a dirt pan. The tank is rusty inside and it being 100 gallons plus capacity there is always trash in there. The original pickup line broke off in the tank so I used the fuel gage penetration to install a different pickup with a screen on it, a strainer and then the inline fuel pump. I've had no problems with fuel starvation since installing those changes.