Machine is a 2006 Volvo EC25 that is new to me, with 4000 hours. Machine starts and runs ok, digs with power; as in you never really hear the engine bog down while using the bucket. Traveling is a different thing. I just sorted the wiring and got the two speed working, same issue in high and low. If I feather the drive controls, it moves ok. If I just push them full forward or back (not abruptly, but a steady move to full) it causes the engine to load up and stall. A probably separate issue is that the right drive will just stall out occasionally, usually when turning. I imagine it's either running over the relief (assuming the left and right drives have separate reliefs) or leaking past a seal in the pivot. But what would cause it to stall out? I have read that there is a load sensing valve. For this to be functioning correctly (pump pressure increased to meet demand) the engine should be at max RPM correct? The throttle control has been hacked, and I am wondering if the max RPM. I am getting is high enough. FWIW, I did find a factory manual on line. It's 2000 pages and full of schematics, but the layout is not intuitive or user friendly. I also have just picked up a gauge set, and am struggling to figure out which test port is for what circuit. Is there a way to test the center pivot? Maybe test line pressure at the pivot inlets, compared to at the drive inlets? Any help is appreciated. I've been fixing and using bobcats for 15 years, but this machine is 2 steps more complicated. SD
First things first. Just how tight are those rubber band tracks? Do you have the ops manual?
I do not have the operators manual, just a repair manual and parts diagrams. The tracks are tight. Too tight maybe? I have no clue, they're as it came to me.
See if your dealer can provide spec's for track sag. They should be snug, so you don't drive out of them. They shouldn't be banjo tight though. Good luck.
I agree it sounds like the tracks are too tight, raise the machine off the ground and drive it in both high and low speed and see if it still bogs the engine while it's off the ground make sure you have two to three inches between the track and your center roller.
My rule of thumb on Mini ex rubber tracks is.........swing to the side your adjusting and raise the track off the ground and adjust your tension to where the inside tread surface (where your lower rollers will be making contact) is 1” from the center lower roller contact point. This is usually a good snug fit without being too aggressive. This also makes the tracks tight enough that they won’t roll off your idler when traveling on a slope sideways or when doing aggressive cross-steering in soft soils.
Thanks for the advice about the tracks. Factory spec is 90-100mm of sag, I checked this morning and have half of that at most. I'll loosen it up, check, and post my findings. It's not surprising, the previous owners repairs have seemed to create as many issues as they've fixed. That they would over tighten the tracks is expected. I spent a few days with the wiring diagram, removing switches and splices. The root cause was an import replacement ignition switch that didn't provide voltage to the correct terminals on its plug. Though, I can't complain much, as the electrical issues were why the machine was bought cheaply
Let us know how it shakes out. Good luck
Loosened the tracks a bunch and it is 90% better. The engine does still bog down some, but is not nearly as easy to stall. At this point, I can at least use the machine while I trouble shoot the cause. I still suspect that the RPM is low, so I ordered diesel tachometer to check it. Thanks! SD
OK, as suspected, the RPM was low by about 500. Seems that the high limit stop screw (which has a tamper proof cap) had vibrated loose and in. The machine was not even pulling 1800 rpm. Adjusted it up to 2300 and all is better
Further update. Took it out to use picking through a giant pile of logs, and clearing a path. Machine would bog when pushed hard. I looked the governor over and found the issue. Top of the housing was broken where the governor spring adjustment is. The screw still had the tamper proof cap, that hid the break from view. Some tig welding and JB, and I'm back in action. I have it adjusted so the governor has to spin hard to cut fuel, and the machine digs and pushes with a ton of grunt now.