Hey all,
It's been a while since I did much sawing, but I recently picked up a loader that will definitely help moving logs and basically anything else I need to move.
I have gotten my hands on a Waldon 7000 loader which I think is a 1995 model. Although, I believe the engine is newer than that(1999?) due to the in-line Bosch injection pump, rather than the rotary style shown in the parts book for the 1995. But that may be another thread. :)
Anyway, i only know a partial history of the loader and it supposedly ran when it was parked due to an upgrade at the plant.
After initially getting it started, the rack stuck and it ran away. I did get it shut down fairly quickly, but I have not been able to verify any loader functionality yet. Injection pump was rebuilt, injectors checked, lift pump and shut off solenoid replaced and fuel tank cleaned. So engine wise, I am very close to starting it up once I get it wired up and the injection pump back in it.
The wiring on the loader was a complete mess. Half the dash was gone, and at some point the main harness had wrapped around the driveshaft and did not win that battle. A fast and dirty repair was done but basically, all that was still connected was forward/reverse and the starter. And at some point, the original joystick electric over hydraulic bucket controls where switched out with a conventional 2 spool valve.
Fortunately I have a parts manual which includes the wiring diagram, however I do not have a service manual.
But to the basis of my questions...
The tram motors and speed controls. The motor/valve in the very front has two solenoids on it(top and right side). One is the Dynamic braking, and the other is for the front motor Shift Override. I am not sure which one is which. The Dynamic Braking gets voltage whenever the loader is in Forward, and the Shift Override is/was connected to the "C"(common?) of the 3 position rotary switch(Low/Mid/Auto).
The "L" terminal of the 3 way switch shows connecting to the rear motor Shift Override. Along with a diode back to the common terminal. There is ignition power applied to the "B" terminal of the switch. There is a "R" terminal that is not connected.
There is a small free standing solenoid valve just behind the steps on the left side of the cab. Parts book shows it is a "Shift Valve" and connects mainly between the pump and the rear motor. I assume that is the rear motor Shift Override.
So...
Which of the two front motor solenoids are which and is there an operational explanation of them?
Is the rear motor solenoid the one I think it is? How does it operate?
Would anyone have an operational explanation of the 3 modes - Low-Mid-Auto"? I am not sure which terminal corresponds with which mode selection.
Does applying the brake somehow work as a de-clutch for the drive motors?
What type of diode do I need for the 3 way switch? Is it the same diode used on the starter interlock relay?
Anyone have a service manual for it? I think the frame sn is 23938
Lastly, Thank you.
Wow it sounds complicated. Sorry i cant be of much help.
I have the machine running now and the good thing is that it will move without those 3 solenoids connected at all.
Yay.
However, I still want to figure it out and make it right.
Now that I have it running, I can play around with it and figure out the different modes. Unfortunately, I have a problem with the steering that I need to fix 1st.
Maybe the steering system is "generic" enough and someone here might have some valuable insight.
The loader has a single steering cylinder and the steering unit connected to the steering wheel. Oil is common hydraulic oil and supplied to the steering unit from one of the hydraulic pumps.
On flat ground sitting still, the loader will steer good and hold position in one direction(left), but when I steer in the other direction, it very weakly steers in that direction, but kind of drifts back towards center. I can spin the steering wheel faster to get it to move more, but it never got to full lock. Like the oil was not pumping, or was bypassing.
It was late, so I did not troubleshoot anything, but I plan on reversing the hoses going to the cylinder tomorrow to see if the problem stays with the loader steering direction(right), or if it stays with the direction I turn the wheel.
If the problem stays with turning to the right(turning wheel to the left), I imagine my problem is in the cylinder. But, if I am able to steer the loader to the right, by turning the wheel to the left, and NOT able to steer the loader to back to the left very well, the problem must be in the steering unit.
Correct?
Thanks
Does it use an orbital steering valve? Short column goes into it, mounted by faceplate to the back of the dash usually.. . 4 or 5 hoses total on the valve.. All on one side in my experience.
Is this thing open center hydraulics ?
Well, after reversing the steering lines at the steering unit, the problem remains with the direction I turn the wheel, not the direction the loader is steering. It steered fine to the right, and not so well to the left.
Looks like the problem is in my steering unit - which happens to be leaking anyway, so I want to eliminate any leaks that I can.
Now, I just need to source a kit or complete unit
As pictured... The two lines on the left go to the cylinder. The one on the top right is the drain back to the tank. The larger one on the lower right is the supply from the pump and the one in the bottom middle, below the relief valve, provides oil to the implement control valve.
These do not look like any that Danfoss shows, perhaps another brand?
(https://forestryforum.com/gallery/albums/userpics/33292/WaldonSteer1.jpg?easyrotate_cache=1532869165)
(https://forestryforum.com/gallery/albums/userpics/33292/WaldonSteer3.jpg?easyrotate_cache=1532869207)
(https://forestryforum.com/gallery/albums/userpics/33292/WaldonSteer2.jpg?easyrotate_cache=1532869129)
Yeah its an "orbital" or "orbitrol" type steer valve and it probably needs seals or some internal work. Im not entirely certain what is inside them but theyre pretty standard fare unless a manufacturer had a non standard mount face put on to make it a proprietary part.
To replace it with another brand you need to know its cubic volume, face mount pattern, steering column spline count and size, port sizes (SAE Oring or NPT?) and how many ports. I think they come in power beyond or non PB but im uncertain. Youll have 1pump, 1 tank and an A/B work port pair. If there is another line it is a power beyond to feed a downstream valve. There will also be a relieve valve cover of some type.
Forklifts and wheel loaders are the most common place to find them in my experience. Id pull that, use EZ bake oven cleaner to get the paint off the numbers tag then tear down and see if its some seal or trash you can just fix.
I am still trying to ID it to find it cheaper, possibly. The only information on the tag are the numbers stamped into it. 5 143 95 04.
Any painted information is long gone. It uses an OLS A 80 priority valve, so it it not quite a "basic" orbital valve.
(https://forestryforum.com/gallery/albums/userpics/33292/Danfoss3.jpg?easyrotate_cache=1533072558)
I think I found the culprit to my problem, and i think I have a correct parts breakdown. I wonder though, if it is worth rebuilding?
New one is over $1k - So I think it may be.
(https://forestryforum.com/gallery/albums/userpics/33292/WaldonSteer4.jpg?easyrotate_cache=1533071692)
These items look to be #26 and #27. Could this be all that is wrong with it(really only one of them looks bad)? It is really the only thing I found, other than the #1 lip seal pushed out.
(https://forestryforum.com/gallery/albums/userpics/33292/WaldonSteer5.jpg?easyrotate_cache=1533071704)
(https://forestryforum.com/gallery/albums/userpics/33292/Danfoss2.jpg?easyrotate_cache=1533072034)
(https://forestryforum.com/gallery/albums/userpics/33292/Danfoss.jpg?easyrotate_cache=1533072017)
The priority valve just ensures you always have a minimum fluid volume reserved for that device.. They put multiple functions on one pump section and dont want to have a dead spot when 2 are used simultaneously.
Id grind off that mushroom, weld and reshape the tip until it matches the other and run it. Preheat and post heat to the first color change.. Just incase its hardened. No quenching.
Thanks for the tip! I understand the need for a priority valve, but I wonder if I could substitute a separate priority valve and orbital valve, it the interest of parts availability.
I had not considered that option of welding.(I really need a TIG machine) I did however, find more damage...
Under two of the threaded bushings. Man, I really wish I could ID this thing better. The breakdown the MFG gave me does not have all of my parts shows, so I assume it is a different model.
(https://forestryforum.com/gallery/albums/userpics/33292/Danfoss1.jpg?easyrotate_cache=1533170958)
(https://forestryforum.com/gallery/albums/userpics/33292/Danfoss2~0.jpg?easyrotate_cache=1533170947)
(https://forestryforum.com/gallery/albums/userpics/33292/Danfoss3~0.jpg?easyrotate_cache=1533170989)
Thats your issue. The ball and seat leak. I dont exactly know how "orbitals" work but that much is obvious, that its a one way check valve that isnt one way checking valving any more.
You could PROBABLY temp booger it back to some what service by machining that seat with a countersink and shimming the spring. Im not certain what caused it.
Probably no need to fool with the priority valve, just get a replacement steer valve. Howe does a lot of this stuff for rock buggies
CHARLYNN FULL HYDRAULIC VALVES | Parts Categories | Howe (https://www.howeperformance.com/parts/charlynn-full-hydraulic-valves/)
Do away with the orbital and make it a stick steer.
Or that. You can still use a wheel or T bar, just use a cylinder spool valve.