Komatsu D65e-6 overheat

[jasonharville]

So have you taken your pump off and looked at it?

Not completely but i took the intake pipe off and saw that fluid runs through it on its own free will.

 

[Cmark]

So what we call in the trade; "shooting it with the parts cannon". Definitely a second tier troubleshooting procedure, but I most sincerely hope it solves your problem. If it doesn't, please post back here with absolutely no prejudice.

 

[Delmer]

And throwing parts at something has it's place, like a lot of cummins parts are cheap and easy to get, so why not just put a different fuel pump on it? that doesn't sound like the case with this transmission pump.

Maybe the fluid running through means it's toast, I don't know. I'd be more comfortable seeing the insides if there was a lot of money or time involved.

 

[jasonharville]

I get what you are saying, but I've already spent hours troubleshooting the usual causes based on the service manual and suggestions on this thread, so I feel like the pump replacement is a bit more educated than a shotgun approach. I feel like I have enough red flags to spend the $300 on the pump. Here is what I know thus far based on troubleshooting:

• Very low fluid volume to the oil cooler.
• Pressure readings are correct at the trans filter(300psi) and at the regulator valve on the outlet of the Torque converter(50psi) and the valves I have checked seem to be in good working order.
• No evidence of TC flooding with initial fluid draining test.
• No strainer on transmission and based on amount of dirt/decaying debris I had to dig out of the belly pan it has probably been without strainer for very long time.
• While trans pump is running there is a 10-15 degree increase in temp between inlet and outlet port. (
• Oil in the pumps inlet port quickly leaks through the pump when it is not moving. ( I know this may not be a very scientific test but the steering gear pump prime issue taught me that a gear pump needs tight tolerances to properly function.)

So based on the evidence I have, I know that I'm achieving the 300psi pressure required but not receiving high enough oil flow to the cooler circuit. Either the volume of fluid is escaping somewhere that I haven't checked or the pump is not producing the volume required. I would prefer to confirm the actual volume output of the pump but I can't think of an easy way to verify that without some elaborate rigging.

If there are other first tier troubleshooting steps let me know. ;-)

 

[ATCme]

Looking at my service manual the main filter comes after the transmission pump. If your transmission strainer is gone then the pump has been sucking directly from the pan with no filtration. My guess would be a bad pump.

 

[John C.]

What people are getting at is that it doesn't take much to remove the pump and tear it down for inspection to be sure. Just might need a seal kit because the overheating cooked them out.

 

[DMiller]

Any good hydraulics shop has the machinery to bench a pump, can flow and pressure test it ass needed. My old trans pump was hard to get to take suction, once I got the suction line leaks stopped the pump still would not self prime, clearances had opened so far it would bypass internally.

 

[jasonharville]

Any good hydraulics shop has the machinery to bench a pump, can flow and pressure test it ass needed. My old trans pump was hard to get to take suction, once I got the suction line leaks stopped the pump still would not self prime, clearances had opened so far it would bypass internally.

I wondered about flow testing at a shop. Good to know for future reference. The new pump is supposed to deliver tomorrow. I know I'm basing the replacement off of partial evidence and I appreciate all the input on how to make sure I'm not wasting money. I haven't dealt with heavy machinery very long but I've had my share of ag tractors and I've had to replace hydraulic pumps more than any other component....and always with good results. I guess that might be due to my tendency to buy cheap/abused/neglected equipment. ;-)

 

[jasonharville]

The new pump is pretty but unfortunately did not solve or even improve the overheating issue. The only obvious answer is that the new pump must be defective. Kidding of course. Before I took the old pump off, I decided to double check the flow to the cooler again to confirm the dribble. Got surprised by a spray of oil. The difference between the first and second test was about 80 degrees fahrenheit. I am wondering if this may also point to my torque converter flood test being faulty. Could the torque converter leaks/flooding only be occurring after the fluid warms up and get thinner? I am running out of causes but will continue troubleshooting today. Hopefully without wasting another $300.

 

[Junkyard]

The oil temp could very well be another contributing factor. Often with older unknown machines you end up with multiple issues manifesting themselves in strange ways. I've dealt with it before. Heck most of us have. On the D11 what was thought to be cylinders bypassing was a pump etc as well. Worked ok cold but much temp and it went to crap. Even if you end up throwing a few parts at it you've done a great job of troubleshooting and relaying information. That's worth a lot, often people come here for help and argue with advice, don't follow suggestions and hope they can order a magic wand off EBAY and fix it.....

There's a thread on here kinda like that but I'm not gonna name names

Also, about the time you think you've been completely stumped you'll notice something or recall something and whatever that pesky little widget is will be the answer. I've had that $hit wake me up in the middle of the night.

Good job so far, I'm sure you'll figure it out!

Junkyard

 

[jasonharville]

Thanks. There were a few curse words uttered this morning as the guage passed 190. At least I am getting very proficient at removing the floor panels and the belly access panel. Also learned to tie some twine to my wrenches as a quick way to retrieve them from the belly of the beast.

 

[Scrub Puller]

Yair . . .
I have been watching this thread with interest as the O/P has been methodical and logical with his approach.

There is little I can contribute as my experience with these tractors was very positive and they had few issues . . . although one thing does puzzle me.

I see mention here of "oil cooler" as though it is an oil to water heat exchanger . . . my recollection of the power shift D65 is a separate narrow oil radiator on the left hand side looking from the front.

Maybe my memory is wrong and that was a different machine?

Cheers.

 

[jasonharville]

While I have not fully traced the lines on mine, the parts books and service manual both refer to an oil cooler/heat exchanger for the trans.
Today I left the footboards off while operating and discovered something interesting. I have a fair amount of fluid leaking from around one of the shift levers at the top of the trans. Based on parts diagrams it doesnt look like those levers should have any oil pressure on them. I also checked the trans fluid level around this time(with engine running) and the fluid levels showed high. The trans valve assembly is something I havent checked yet and fluid must pass through it before getting to torque converter. Any chance I could have a trans flooding scenario?

Tomorrow I will check fluid levels at various points during the heat up process. I am aalso going to try to confirm good fluid volume on the cooler return line since this lastnight I discovered the flow TO the cooler is much better when the fluid is cold. (Made quite the mess)

 

[Queenslander]

Have we absolutely eliminated the coolers as being the problem?
I have a Fiat Allis dozer that presented exactly the same symptoms.
Shot it with the parts cannon, but it wasn't until we found both the engine and transmission oil coolers 30% blocked, that we solved the problem.

 

[Cmark]

In a torque converter powertrain, the vast majority of the heat is made internally by the torque converter. If you feel the transmission case getting hot before the torque outlet valve, you've got something wrong.

Just to clarify the discussion about flooding the torque converter in either an excess internal leakage or faulty scavenge pump scenario, the heat in this situation is caused by the case filling up and the torque converter running in the oil. If this is happening, the case will quickly get too hot to touch and the extra drag may be noticeable as loss of power. It may even bring the engine temp up as well.

 

[jasonharville]

Queenslander. We have not. It think my troubleshooting has been muddied by doing various tests at random/different operating temps. Now that i know there is good potential flow to the cooler with cold fluids, I am going to try to check the volume on the return line while it is still cool.
I have tried to pinpoint the source of the heat and it seems to be the TC. Once I get to overheat territory the temps are all about the same on every component with the pump outlet showing +10 degrees to the rest of the system.

 

[Queenslander]

jasonharville, Iam probably barking up the wrong tree, but on our tractor, it was the coolant tubes that were blocked in the coolers, so oil flow wasn't affected.
Both the engine and transmission temps would rise together, overheating within an hour.

 

[jasonharville]

Hey guys. Sorry I haven't posted much I've been kind of frustrated. I haven't made much progress with the overheating research because the tractor started doing it's shut down thing again. This time it's happening more frequently. It will usually run for 30 to 45 minutes when it's been sitting for a long while but gets more frequent with use. When it stops it does so abruptly just as if the switch is turned. Let it sit for 5 minutes and it will usually start up again and run for 5 minutes or so then shut off again.I started troubleshooting the fuel delivery system and found moderately clogged drain assembly on the fuel tank. I also found a complete lack of fuel screen in the fuel tank and there is also no fuel filter or water separator in the system so I am suspicious that I may have some trash further down the line or even in the PT pump. I thought for sure i had screen/filter clog issue bc of the way it is acting. But if I had gradual clogging going on i would think it would act fuel starved for a bit rather than quick shutdown. There is a fuel solenoid valve in the inlet of the pump. Going to investigate that today.

On the overheat topic, i checked outlet volume on the oil cooler circuit. When fluid is cold the is plentiful volume coming through the return line. It seems as the fluid warms my volume to the cooler decreases. I guess that means the thin fluid is finding places to escape. Should I go through the effort of pulling the trans valve assembly given the leaks observed at the shift lever? I think my only other option is major torque converter issues at this point. Btw, the trans showed overfull on dipstick at all temp ranges. I may have overfilled it at some point...i am not sure. I wish there was a way to check TC fluid levels at the same time.

 

[jasonharville]

Well scratch that. I just found some filters in an hatch to the left of the drivers seat.

 

[ATCme]

Well those don't look factory. I have one big filter in the same spot but i don't think it has anything to do with my transmission?
You replaced a pump but was it the scavenge pump or the transmission pump? Fluid in the T/C case should be minimal. The few times i drained mine there was less than a beer can in it of oil.