I’m back with an issue after a year of running the machine I purchased a disk mulcher. I’m having an issue with tilt and arms where they are bleeding of with the attachment on. This machine has all new fluids and filters less than 3 hours on them and I don’t know what the culprit may be. Any guesses?
All hydraulic systems are bleeding off almost as if a load brake or load control position is not working correctly.
If you disconnect the hydraulic hoses to the mulcher does the problem stop.? Is the mulcher plugged into the quick couplers on the lift arm.? How many hoses.? This the same machine FMT00336 as before.?
Yes same machine. The lines aren’t connected to the mulcher I tried that first. It’s almost like a stuck relief valve for the manifold I believe because all the cylinders on that manifold are doing the same thing. I noticed it wasn’t driving right trying to unload the machine and then once I got weight on it the arms down is aggressive and chattery if you try to go down slow. I was offloading a trailer today and found the arms and bucket controls are not functioning right. I’m going to check pressures again tomorrow on the main relief valve and implement manifold but it’s weird to just all of a sudden start doing it with a load on.
I’m going through the hydraulic schematic at the moment to figure out a game plan for tomorrow to try and diagnose the issue. It’s only with a 2000lb mulcher coupled on the front do I have the issue all the other smaller implements don’t do it. The oil was getting warm too at about 160* when this started happening.
160* is only nicely warm. If it was really heating up it would be up around 230*+
Yeah on a warm day it was 13 today and it usually stays around 140-170 if I’m really using it. Today it just idled around most of the day some rabbit mode driving. One thing that did catch my eye is the fan wasn’t blowing out the debris on top which it usually does so there is a few things I’m going to look at tomorrow. My diagnosis is it’s something in the charge system not holding pressures on the spools in the manifold. I’ll replace the filters again after cutting them to see what’s going on maybe the fluid is cavitating at the charge pump but it doesn’t feel super thick.
The arms down speed is what really worries me it could cause a lot of damage to my implements doing that it was almost as if it was a free fall slamming into the stops.
Sounds like your cooling fan might not be turning fast enough. Oil that starts to get hot can cause problems. Is that rad very clean. Is the rad cap full to the top, not the overflow tank. Did you take apart the last hydraulic filters you changed and checked the paper pleats for pieces. Simon C
I did the filter was good. I’m going to pull it Apart tomorrow and check another one. I’m wondering if the fan quit I didn’t open the door because I had to go to work but I’m going to do the usual checks tomorrow to see what I may have. The strainer in the tank was plugged up with crud the last time I flushed the entire system with new oil through a secondary pump I hooked to the auxiliaries and filtered the oil that way removing water and deposits if there was any. I didn’t cut open those canisters because I don’t have a tool for that but I might get new ones and run it again.
A lot of needles and small debris on top that usually blows off
If your fan is not working well, that would be a good starting point along with cleaning the rad and checking the coolant level. Have not checked the schematics to see how the fan solenoid works and if disconnecting will put the fan full speed. Simon C
Unplugging the demand fan solenoid will set the fan to full speed.
Filter is clean with no debris. Unplugging the fan I get nothing fan isn’t moving. I’ll check charge pressures.
A fan that doesn't move will cause some problems. guaranteed. Once it is running you will be able to reevaluate everything. Simon C
the fan is spinning now on a cold start. Pressures are good but all arm and tilt cylinders are bleeding off. A 2k lb mulcher shouldn’t be doing that. I wouldn’t think all the cylinders have just gone bad if I shut the machine off or engage the lockout they still slowly drop. These solenoids on the manifold look like they have been replaced before do they need calibrated after they are installed? That might be the issue with rapid dropping with weight. The only thing they all have in common is a single relief valve on the manifold I wonder if it is damaged or stuck slightly open allowing the pressure to drop.
You would think if the spool returned to center they wouldn’t allow them to drop given the ports are blocked unless the individual reliefs are all messed up but I find it hard to believe all of them failed
If I understand you correctly all these issues started after you installed the mulcher for the first time. I wonder if it is possible that there was some contamination in the mulcher lines that was picked up into the control valve.? Only a disassembly of the indivudal solenoid valves and the control valve body would answer that question.
I’m wondering the same thing. It’s a brand new mulcher but something isn’t right.
How hard should the fan motor spin? I took it apart there is no scarring or wear on the walls or the gears. It’s not easy to turn but it does spin
The spec. on the fan speed with a photo tach, with Hydraulic oil at normal operating temperature is 2690 plus or minus 50 RPM, according to Nige on the last persons inquiry. Could be wrong, check to see how close. Simon C
I found it, previous owner must have flipped the internals using the gears as a pass through instead of going around the housing like a normal pump. 400 psi will move it but without control given the filter side would pressurize and the pressure would plateau due to the check valve in the fan if the pressure is equalized then the solenoid would not function given the pressure needed to overcome the filter line side of the motor.
Amazing I’ve ran it this long like that with no issues. When I checked my charge pressure it was within spec but now I’ll have to adjust with the fan working properly.