I purchased a M135GX with 450 hours, had a kubota shop mechanic service the tractor, oil, air and hydraulic filters changed, hooked it to a 6.5 yard scrapper and began to build a pond dam, worked great for 3 weeks, then the issue started, under a heavy load the engine would start choking down, if i decreased the load it would recover and run as expected, gradually began to get worse, dropping gears doesn’t seem to help, but cranks and runs fine until under a load, had kubota mechanic come out run full service again, oil, fuel and hydraulic oil and filter change, no help, starting to trouble shoot, any suggestions, doesn’t seem to matter if engine is warm or hot, when i first started pulling the scrapper, it would pull hard in Medium 1st gear, now it want pull in low. When choking down, engine rpms are dropping until engine dies or load is decreased
M135GX Loosing power under load
- Thread starter Hfoster
- Start date
Most of these type problems are caused by inadequate fuel delivery. Restricted fuel flow can start in the fuel tank at the outlet. If you are operating in cold temperatures and with a non-winter type fuel, it could be waxing. I can also be from bacterial contamination of the fuel. These bacteria live in the fuel/water interface so make sure you manage any possible water (condensation in the tank, contaminated fuel from supplier, etc.). Crud (insects, manufacturing debris, straw, etc.) in the tank is also a possibility. To check for this, disconnect the line from the fuel tank to the filter and holding a suitable container under it look for a steady full flow of fuel discharging from the line. If it is not full flow, dribbles or is intermittent, you found the problem. For a temporary fix, blow back toward the tank to unclog the strainer. This can get you running again but it's temporary. You said the filter was changed but the passages in the filter head ahead of the actual filter can clog so check that also. If you have a lift pump, many have screens that can clog, or the pumps themselves can fail. To check that, disconnect the fuel line downstream of the lift pump and crank the engine over. Again, you should see a lot of fuel come out of the line. I generally perform these checks by removing a line downstream of the lift pump and working back toward the tank. Also look for loose fuel fittings, cracked fuel hoses or lines, clogs in the hose or hose delamination.
I don't know what type of emission controls you have but that could also be an issue. Also check the air filter for clogging, though from your symptoms, I don't think that's the issue.
I hope this helps.
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Yes sir, thank you for your response, I'm going to start trouble shooting the fuel system, this model has the EGR / DPF which has appeared to be working properly, when the regen light comes on, takes about 15 minutes idled up to complete the clean cylce. this has been a gradual thing and slowly started getting worse. I'm in Northeast Texas and have been adding seafoam to every other tank of diesel. The algae may be the culprit, was hoping the seafoam and regular filter maintenance would be a preventative but obviously not. Thanks again, any thoughts are appreciated.
RCW
Well-known member
Lifetime Member
Equipment
BX2360, FEL, MMM, BX2750D snowblower. 1953 Minneapolis Moline ZAU
I agree with Jerry - - -It's a fuel issue of some type.
Your tractor's fuel system is much more complicated than I can advise.
Did you notice anything in the fuel filter that was taken out? Any black staining? That could indicate algae.
Your tractor's fuel system is much more complicated than I can advise.
Did you notice anything in the fuel filter that was taken out? Any black staining? That could indicate algae.
BigG
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l2501, FEL, BB, Rotary cutter, rake,spreader, roller, etc. New Holland TL80 A
I was wondering if they changed the fuel filter and the water separator filter. Just looking at the parts book it looks like you have both. I had to change the water separator filter several times in one day to resolve a loss of power issue. The new filter was damaged by the water and restricted the fuel flow. If you looked at the filter it still looked new but it would not let fuel flow fast enough to keep up the high RPMs. The third filter let it run.
Diesel form of "Dry Gas" helped also.
Diesel form of "Dry Gas" helped also.
You need to treat the tank with a biocide if you find evidence of bacterial sludge. Keeping the fuel tank full will minimize condensation which is generally the source of water that leads to bacterial sludge. Especially if you live in a humid climate. You can't eliminate condensation but you can manage it. Drain your water separator or fuel filter occasionally. If you drain it in a clear glass jar, you can see the water in the drainage.
I agree with other members in that it sounds as if fuel supply from tank to inj pump is restricted. Is fuel tank venting? I suggest to operate with fuel cap removed & shop towel covering fuel tank neck. I owned a M4900 several yrs ago that engine acted similar & I located a tiny screen in water seperater housing that was clogged. Removed the tiny screen & engine ran well when I traded for my M7040
You guys are dead on, kubota service guy came out today (also friend of the family) , disconnected the fuel hose coming out of the fuel pump, it had an arc coming out with about a 1” radius, he said it needed to be pumping out about 4 to 6”, he took the water separator filter bracket loose and there was debrie in the incoming fuel line from the fuel tank, a 90degree bend, there was a grasshopper plug up in the bend, blew it out, then back together, the stream then arced out from the fuel pump about a 4” radius, rained today so can’t test it under load, but the fuel has abought 3 times the flow now, pretty sure im good, thanks guys for the input
Got to run the 135 with the scrapper today, ran like a champ, no power issues at all, still haven’t figured out how that grasshopper got in the fuel line