Hello everyone, I'm struggling with a 340 Case skidder. Don't know if it matters but it is equipped with ride control, high flow 3rd function, quick attach bracket & A/C . The machine fired up and ran fine, they walked it from the barn to the out building, maybe 100 yards. Set the brake, shut it off and that was that. Now, you can start the machine, boom and bucket work just fine. Satisfy all the safety protocols in order, fat man switch, safety bar, then lap belt. Press the film for park brake, the lamp goes out but there's no travel function. Raise and block the boom, tip the cab. Clean the fuse panel of dirt and mulch. Clean relay sockets as well. Power everywhere you expect. Check charge pressure, 330 @ idle, 425-430 full throttle. Check both solenoids at the brake valve. Used battery power to check coils, they will not grab a screwdriver. I ohmed each coil to find 9 ohms. I had a boom suspension spool, brand new, gravity will activate it. Placed the coil over the stem, no activity. So I'm pretty confident the mag(s) have failed. My challenging question is, why won't this thing stall @ idle if I stroke the sticks fwd against the parking brake? I mean there's nothing. No hoses surge, no load can be heard from the engine. Does this thing have a neutralizer to keep you from trying to roll through the park brake? It acts like it has an inching pedal. I have no service literature on this thing at all so any and all help is appreciated.
Do you know what brand pump is in it? Mechanical link from the hand levers to the swash plate levers?
It's a danfoss M91. Yes it has mechanical linkage to the swashplates. It has a small fluid manifold running from the 2 controls and appears to run towards the park brake manifold.
So, this is what I'm working with. The -4 manifold that runs from one control pedestal to the other gives 18-19 psi running, idle or full throttle. The -4 hose runs to the park brake manifold valve beneath the spool/magnet I'm concerned with. The pressure doesn't change in relationship to park brake applied or not. The -6 line, I'm confident, is charge pressure that feeds the park brake manifold. As mentioned prior, it has 335 psi @ idle and 425/430 @ full throttle. The machine has only 1600 hours or so, and I can't believe both swashplates broke at the same time. I'm leaning hard on this brake manifold, but it's a big pill to swallow. Anyone have any secret squirrel information that could shed some light my way. Thanks in advance
Il I believe, even though you have mechanical levers, that pump uses servo pressure to move the swash plates. Its why, when your in park you get no travel pressure to push against the brake. I would suspect the park brake valve or something tied to it isnt shifting to allow the brake to release or servo pressure for the pump.....or both. I've seen similar systems, especially on rollers
So instead of "neutralizing" like an HST loader with an inching pedal, it's looking for charge pressure from the park brake valve? Does that sound right?
I suspect your park brake and servo pressure are connected......so yes
This is the valve I have. The $1366 one.if it's not shifting , I guess that would explain no change to the -4 manifold up top? So the control lever relies on a fluid fill to act on the servo? Does that sound correct?
Thanks, now, I shall call you Obi-Wan.
From my memory I believe that is the case. Hopefully I'm not send you down a rabbit hole. Does any of this run through a vcu that you know of?
No, it seems pretty straight forward. The closest thing is the ign/switch panel. It just seems to look for logic, seat sw/ arm bar, seat belt etc.i haven't seen a machine controller anywhere.
Those 2 magnets get power but they won't even grab a pocket screwdriver.
Yet they have equal resistance...?
It would be nice to know what yhat operating voltage is for those wouldn't it. If it doesn't run through a vcu I would assure they are operating on system voltage. If that is there, ide remove the cartridge and see if the spool shifts when the coil is hot.
Might pull one of the coils off and see if the voltage rating is stamped on it
That's why I tested it on a new spool I had for another job. Nice and free, no movement when energized. Yes, system voltage, 13.9 or so.
It should move when energized. If it isn't it may have a piece of trash preventing it. Seen that before too
If I'm proved to be wrong on all this.....you will have to sue me lol
They're both the same, but different. Ones got a Deutsch connection and the other has a Delphi weatherpack.
For every nickel I paid, and then some.
That spool should move with a good ground and system voltage. Might try using test words off the battery for hot and ground
I blew through the -4 hose with air. Back through the valve into tank. It doesn't matter if it's released or not, it still blows back to tank.
I did. I have jumper plugs just for measuring and testing. Like I said, the mag is weak m
I am a little late to the party, however I..... ....believe you found the issue.
That's what I needed confirmation on. Since it had mechanical linkage and charge pressure, I assumed it needed the dinky lines to somehow pressurize the control housings. I'm not familiar with it but I'm guessing it's some kind of fluid coupling between the levers and servo piston? Not familiar, but I ordered a park brake valve. Just don't like "not knowing" Thanks for confirming my suspicions.
For reference, the lever just turns a spool which then supplies charge pressure to the servo (the ends where the backup alarm switches are mounted plus the opposite side to them). The servo piston is then mechanically attached to the swash plate.
So for the less intelligent, it supplies pilot oil to pump mounted pilot controls articulated by link and lever linkage? Pretty sneaky sis. So glad I made the right call, accidentally on purpose. BWAHAHA Thanks , both of ya.
Is it fixed?
Waitin on pieces parts
So, got my solenoid stem n coil for the pilot oil . Put my parts in, nice and clean. Still no travel. Check power to coil, it's gone! Where did it go? I chased that wire back to a switch on the left joystick. The switch , evidently disables travel when enabling aux hydraulics. If I didn't know for absolute certain that I had power, I'd be kickin myself. Evidently I bumped it at some point. So it's all better now and thanks for the help.
I had a 340. Travel doesn't disengage when the aux. is engaged. The aux engages on the right handle. None of that sounds right.
Well the button showed a coupler, it completed the circuit to the solenoid, I don't have an ops manual for it, so I don't know what to tell you.
I am just trying to understand how all that worked. The aux variable control switch on the right activates the aux. and it doesn't disengage the drive. The left side is the electric/hydraulic control switches for additional hyd functions. They don't do anything unless the right side is activated and you have a 14 pin plugged in. It makes no sense to me what magic made it work, but at least it did.