4/3/26 - I provided much detail here for maximum benefit to any readers. My questions are at the end, and I will appreciate any helpful comments - thanks. - The Cat dealer just installed a new engine “AR-PR”, Cat part no. 345-3555, in our Cat 299D XHT, serial no. JST000496, because the new one overheated many times and finally died. We learned the hard way that keeping the engine radiator, A/C condenser and rooftop radiator clean takes frequent serious attention, especially when mulching. Total time on the machine is 1601.5 hours. The Cat dealer replaced the engine, all electrical harnesses, the track assemblies and sprockets, hydraulic lines, hydraulic coupling that drives the hydraulic pump, rubber tracks, and other items, and cleaned out the area underneath the cab. The work invoice does not show that any work was done on the hydraulic pump. - The new engine now has about 22 hours, 15 hours of which were mulching with a Fecon Bull Hog BH074SS mulching head. Mulching uses high flow at 40 gpm, with the engine running at full speed on the continuous flow setting. The mulcher seems to use about all the power the machine can produce. The operator was moving forward while mulching, then stopped to reverse direction at which point the hydraulics stopped working. The machine stopped moving and the mulcher lost power. - We never saw any engine codes or warnings while operating the new engine. I believe the codes saved in the system are related to the old engine. I did not see any leaks. - I checked both of the 15 amp hydraulic solenoid fuses, #16 (F6 on the panel) and #19 (F9). #16 (F6) was blown so I replaced it and checked the hydraulics again – still not working. - With the new engine, we blew out the radiator, rooftop cooler and air filter, engine compartment, cab area and entire exterior of the machine with a leaf blower after every mulching session, except for underneath the cab. - Over the last few hours we noticed that the hydraulic oil sight gauge was in the red on the overfull side after mulching, even though it started out in the middle of the green, showing a normal fill level. We added no hydraulic oil after receiving the machine back from the dealer. After noticing that the first time, the sight gauge returned to the green by the next day, with the machine sitting level. However, at this time the sight gauge is pegged all the way to the right in the red, indicating overfull. The machine is facing uphill and leaning slightly to the left, if that makes any difference in the sight gauge indication. - We double-checked for anything that would trigger a hydraulic lockout. The lockout symbol was not illuminated. We checked the door closed, armrests down, lockout switch off, tried the hydraulic interlock override sequence to no avail. The engine funs fine but the machine is dead on the hill. - I talked to Cat technical services on the phone and the tech told me the most likely cause of the failure is that the drive splines on the “14 Teeth Flange Coupling”, Cat part no. 345-3548 somehow sheared so that it is just spinning on the hydraulic pump drive shaft, and therefore no longer driving the pump. The Cat service tech told me the coupling is intended to operate sort of like a “fuse”, presumably to protect the engine in the event the hydraulic pump has a problem. The coupling bolts to the engine flywheel and drives the hydraulic pump. Our dealer replaced this coupling when they installed the new engine. Questions: - Could the hydraulic failure occur by allowing the mulcher rotor rpm to drop too low or maybe even suddenly stalling the rotor on the mulcher, thereby shearing the drive splines on the hydraulic coupling? - Could there be a different problem we haven’t thought of? - Why would the hydraulic oil sight gauge indication rise from normal green to maximum red under use, showing an overfull tank, and how could that be related to the hydraulic failure? - Could the failure be caused by the dealer installing the coupling incorrectly? - Is there a way to dismount the 2800-pound mulcher off of the machine without hydraulics, so we can take it back to the shop?
I’d say that either it was a bad coupling flange or it could possibly have been damaged during the engine installation. The only way to find out for sure is to pull the engine and take a look. Either way it should be covered under warranty. What type of coupler is on the front of the machine.? Manual, electric, or hydraulic.
Think the oil level is showing very high when the unit is very hot because it expands a lot when hot. Have to remember that there is all the extra oil that runs the mulcher that gets hot also. With all this oil expanded it is normal for the oil to rise on the sight glass. If machine is parked at an angle it will cause it to rise more also. Do you have the rear above engine Hydraulic powered fan as the schematic of the back end shows a circle like the shroud. If you have it the fan is suppose to start when machine starts. If it does not then the coupling is gone from my understanding. Simon C
Nige, it is a manual coupling for implements. Simon, thanks - I will check on the fan operation.
In that case unless you have some fairly hefty lifting gear you’ll struggle to remove the mulcher attachment from the coupler.
If you’re going to be in the mulching business, you’re going to have to come up with a plan for keeping the machine as clean as possible. If you don’t, you’re going to have fires literally and figuratively. A leaf blower is a start, barely. Equip a work truck, with a tank, a pump, a gas pressure washer and some other tools to keep the machine clean. That or suffer the consequences. Or bring the machine back to the shop and clean it every day. Unfortunately mulching is a dirty business and learning the process is costly. Learn from TreeMuncher on here on how to set up a support truck and how to keep it clean enough to make money. His discovery of a new tool the other day was enlightening. Good luck.
OK - thanks all for your comments, all well-taken. I figgered removing the mulcher would be fun.
Actually, getting the mulcher off was super easy. We put a chain on the lower padeye near the bottom of each side and simply pulled it off, one side at a time. You could probably do them both at the same time. For Harley Happy - the leaf blower turns out to be the best we have found for daily use in cleaning out the entire machine thoroughly and quickly. We also use the Radiator Genie water and compressed air wands for a deeper cleaning on the radiator when we open it up to get in closer. The wands get in close and tight.
Never heard of the Radiator Genie, will have to look into that. I always have issues with the angles on my radiators and cleaning them.
Same, I put a pretty sharp bend on the end of our pressure washer wand but it was still hard to get a good angle on the spray...
Harley - yeah, yours is the same idea as the Radiator Genie. There are lots of vendors for that. Otherwise, found the problem: The dealer sent a tech out onsite and found that the two bolts attaching the pump to the engine were not tightened. One fell out and was lying in the bottom of the loader; the other was pretty loose. We got about 15 hours of mulching out of it before the thing fell apart and wallowed out the splines on the coupler. So, the tech got to install a new one, onsite - good guy. Everybody makes mistakes, but we should be back in business after he wraps up this afternoon. Nige, you were spot on. Good learning experience for us. Thanks everyone for your input - much appreciated.