The hydraulic hose to the right drive motor blows and was replaced by Waukesha Pearce. They also replaced the HST filter and replaced 25 gals of hydraulic oil. Very limited function test. I ran it briefly and stopped when I received a HST filter clogged alert. I stopped and removed the filter and it had a few small brass shavings and a small glint of silver metallic dust that would not stick to a magnet. Put it back on and it alert again and I limped to a more desirable location and parked it. Engine running perfectly and an easy starter. Next morning returned and had forgotten to turn off the battery disconnect. I tried to start it and the batteries were low but it did start and run briefly but may have had a fuel starvation sound and died. Hasn't started since. Cranks but no start no smoke Tech comes back out and it won’t start for him and he was not prepared to jump but did hook up his truck for 3-4 hours while he was there. He removed the filter/separator and said it was only half full of fuel. He blew the line back from the filter to the tank and initially had significant resistance. He then pressurized the tank and fuel flowed freely to the filter. He returned today after I had drained and replaced all the fuel, changed all the fuel filters, bleed the system and replaced the batteries which the old batteries charged and tested fine. He spent all day today troubleshooting. Rail pressure is good. No codes whatsoever either in Komtrax or when he queried the ECM directly. Bleed the rail. Nothing. Won’t start. No smoke. The injectors are controlled by the ECM. Starting fluid does nothing. It does sound like it wants to start. He wants to come back Monday, pull the hood and manually check the injectors which will take 2 days in certain. It costs me no less the $1000 every day he comes out. I’m thinking of replacing the ECU myself. It’s cheaper than having him come out for 2 days and I don’t think that all the injectors failed overnight! The ECU on the other hand might fail abruptly. It’s either that or something so simple it’s not obvious. I’m getting a bit desperate to find a solution. Komatsu D61PXi-23. When I initially backed it off the trailer I was very pleased with my purchase until the line blew. I’m sorry for the essay but wanted to give you as much info as I can. If you have any advice please do share it! I’ll be forever indebted! Thanks! Kevin
Hope to be helpful to you. The attached file is a section about troubleshooting the engine of the Komatsu D61PXi-23 bulldozer, you can download it for reference. Good luck.
Was this issue ever resolved
Unfortunately, it currently sits at Kirby Smith in McAlister, OK since November. I've spent $15k on diagnostics before taking it there. Three techs at KS have looked at it including checking compression and the last tech miraculously discovered the High Pressure Pump was only making 200-300 psi. They sent it out and tested it defective. It had always tested at 5000+psi prior. I'm waiting on a pump from Bosch. Komatsu gets almost 4k for the pump but the same pump from Bosch is $1200. My confidence is waning! You have ideas?
When the customer sent me the video Friday before Easter it was running rough. When I showed up Monday it would not start at all. Would fire off of starter fluid but die. Check resistance across the injectors found #3 and #6 where at 2.5 ohms replaced them machine runs rough. Still diving back into diagnosing it has no fault codes what so ever
Mine had no codes on Komtrax or through Insight. Waukesha came out three times and had no idea what the issue was. Cummins sent a factory tech out and he did everything they did again. Hauled it to KS and its on the third tech there. I just hope it is the high pressure pump.
Did you ever find the problem on dozer starting I have one hre that's acting similar and seems like the hydraulic pump is the problem, I capped off the sense line into the pump and then cranks easily and starts, not sure why my cooling fan runs nonstop either may be spool hung up??
Check HST charge valve and check the fan spool , comp valves and safety suction on the control valve, sounds like an ls signal is being generated causing fan to go hi speed and ls to be generated when cranking causing pump to load up and over come engine horsepower when cranking
Marcus, What a nightmare this has been. This dozer started and ran fine when I unloaded it from the trailer. It operated normally for over 90 minutes before blowing the main hydraulic hose to the right drive motor. I shut it down immediately. The hose and the HST filter was replaced. I ran it for about 40 minutes before hydraulics became weak and I parked it. Tech returned and it would not start! Two factory techs, a tech from Cummins, and several independents came to assess the machine over the next 12 months. I hauled it to the Komatsu dealer, and compression was low, and they determined it needed an engine. I can't imagine how it operated with good power and overnight it lost compression on all cylinders. I don't remember the numbers but I felt it should have started. I had the engine replaced and on initial start up when operating the work equipment the blade stuck in the up position and the fan went to the max position. further investigation found the piston in the middle of the swash plate in the work pump looked like it had been stuck in a pencil sharpener. Replaced the pump cleaned the tank and all filters. Go to start and run, and the hydraulic oil cooler ($2800 for aftermarket) was corroded and had a pinhole. Waiting on parts now. I've owned this dozer for over 2 years and I have operated it for less than two hours and spent more than I payed for it. I'm a farmer and not new to equipment but this ranks as my worst!
Sorry to hear about your loss, but if you want to learn something from it, do not ever buy a used piece of equipment without taking quality samples from the engine, hydraulics, bevel gear case, and final drives. If that takes you a full day and $250 of sample bottles, that will be comparable to toilet paper to wipe your rear in comparison to having to get into all the major repairs you are into. I did this for a customer who wanted to buy an excavator, costed him $500 total. Samples were horrible, failed totally, customer backed out of purchase and thanked me for the privilege that he did not have to be screwed over. Simon C
Oh, believe me, I learned a lot from this experience! And you are correct; sampling fluids is essential. I do samples on all the equipment I already own! Never again will I make that mistake. Unfortunately, the dealer did send samples, and I can honestly say there was nothing that would have prevented me from purchasing based on the results of the engine oil, and I'll never know because I drained the hydraulic oil tank after the line blew and it sampled clean but it was new fluid. I have had the final finals out to drag it around and load it on the trailer. The dealer didn't do coolant but its all new now. Buyer beware!
I honestly am shocked they put a new engine in, It would have been interesting to now what's the rail pressure was and the bleed off from fuel pump and Injectors.... Also interesting the pump was changed after, normally if it's not a stuck injector causing fuel to dump or pressure dump valve on rail which you know (cause it won't build rail pressure and start) you cap ls line to pump or slip the pumps off the back of the engine on these tractors. Very bizarre troubleshooting
Oh, all that was good. The high-pressure fuel pump was good. The pump that failed was the work pump that drives the blade. The only thing that didn't jive was compression. There were no codes on Komtrax or directly through the ECU.
Its always a good idea to shoot WD40 into the air intake to lube up and increase compression to see if it starts. Don't always know what someone else has done with either, drying out the cylinders and low compression. Takes all of 2 minutes and no cost. Simon C
Yeah I understand that, even when the pump is good and an injector sticks or rail pressure dump does they won't throw fault codes or log it, just weird that the engine lost all compression, never seen an SAA6D107 loose all compression, I've seen broken valve springs, bent rods, broken cam shaft, fed turbos, never seen one loose all compression, usually when they do what they've done and don't start it's been injector stuck causing leak off or pump loading the engine up with ls signal
It is like you’ve already covered a lot of ground. Since there’s no smoke at all, it does point to a fuel delivery or electronic issue. Before swapping the ECU, have you checked the wiring harness and connections to the injectors? A bad ground or coffee pods starbucks loose connector could explain the sudden failure. Might also be worth checking for any security lockout or ECM reset procedure.