Resurrecting a Waldon 7000. Electrical/hydraulic question.

[Steve Bowman]

Hello,
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. I plan to use it around my farm.

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.

 

[Steve Bowman]

Well, it seems that I may be on my own here. I suppose this thread will serve as a place for me to figure it out, while providing some information for anyone else who might encounter a similar situation. Maybe, as more information is learned, someone will come on board with me.

I ordered a substitute switch, but was unsure how to wire it just from the schematic. I needed to be sure how the terminals on the 3 way switch worked. Due to internal corrosion, there was no continuity between any of the terminals in any position. I thought I could disassemble it and learn the functions. However, I was able to disassemble it, clean and rebuild it. The original switch now functions just fine.

Now, I know a little more, but still not enough about the drive motors to figure out how the functions work.

The diode turned out to be OK and is connected between the front and rear motor connections. I believe I have it connected properly. But with a 20 year old machine, I won't take it for granted.

So, I still wonder what effect the energized solenoid has on the motors?
And, what the switch changes - speed, torque, or something else?
Front motor is 80cc, and the rear is 55cc.

The 3 modes - Low-Mid-Auto are connected as follows.
Low - 12v supplied to BOTH the Front and Rear Motor Shift Override solenoid
Mid - 12v supplied to ONLY the Front Motor Shift Override solenoid
Auto - no voltage is applied to either solenoid

Would it be likely that energizing the solenoids activates a low flow condition?
If this is the case, in Low, both motors would be in low speed. In Mid, only the front would be in low speed, which might more closely match the displacement of the rear motor. But in Auto, bot could be assumed in high speed, but why not call it High, rather than Auto?

Just for the sake of verifying the connection of the diode... If I where to reverse the diode, these conditions would occur...
Low - 12v supplied to ONLY the Rear Motor Shift Override solenoid
Mid - 12v supplied to BOTH the Front and Rear Motor Shift Override solenoid
Auto - no voltage is applied to either solenoid

So, in this case possibly energizing the solenoid could activate a high flow condition? With the smaller rear motor in high flow, it could more closely match the front for a "low" speed? When both are energized and in high flow, it would be Mid speed? But that does not extrapolate to the "Auto" which would have them both in low flow if this where the case. I do not think this would be correct.


I suppose I could track down the make and model of the motors and find more info on the solenoids that way, but who wants to take the easy way out? lol.

Thanks

 

[mikebramel]

I had one of these but dont remember the details. I though mine only had one motor that was split by a transfer case. But when the motor is "shifted" the swash plate is shifted so it changes displacement. High ranger would be smaller displacement. Less torque and more rotations per input of fluid. Low range would be larger displacement. More torque and less speed per fluid input

 

[mikebramel]

Service manual was like $50 or something from Waldon

 

[Steve Bowman]

Front motor is a AA6VM80HA 1R1/63W-VSC527A
Rear is a AA6VM55HA1T/60W

Have not found those models on the Rexroth site yet.

 

[Steve Bowman]

Here is the front motor. I have to determine which solenoid is the dynamic braking, and which is the shift override.
The "top" solenoid has a line that comes from a similar block on the rear motor. However, there are no solenoids on the rear motor. The solenoid on the right(left as pictured) does not have any hose connected near it.

 

[Steve Bowman]

Service manual was like $50 or something from Waldon

Do you happen to remember if the manual went into detail in regards to the rebuilding of steering units?

 

[mikebramel]

No I dont think so. It had wiring diagrams and theory of op, but wasnt a component rebuild manual

 

[Steve Bowman]

Well, after lots more work than I had anticipated, I have what I think is a very useable machine. I still have to address some bushing bores where the boom cylinders attach to the boom, likely involving line boring.

I completely rebuilt the center pins and articulation assembly. The bores for the spherical bearings where tight, but the pin bores in the main frames where worn. Not really wanting to line bore those, I took a shortcut and made some 3/4 thick bushings that I welded on, and I made my pins longer to accommodate. I have found that one of the grease holes in the original pins was not in the correct location and the bearing probably never got any grease.

I also had one end of my steering cylinder that was beat up very badly. Rather than welding it up and boring it, I bored what was left to accept a bushing, into which the spherical bearing was installed.

I also replaced the faulty orbital steering valve with a new one and also the main hydraulic valve with a donor from a fork lift.

I just got it all back together but still have not tackled the solenoids from my initial questions. Soon I will put my mind on that task, but in the mean time the loader runs around just fine.

 

[Steve Bowman]

 

[Steve Bowman]

Although there are two separate pins, I used one long pin ro align my bushings before I welded them in place.



Should be plenty good for life around the house lol

 

[Steve Bowman]

The "new" tires and wheels definitely change the look of the loader for the better. They where skid steer wheels with the wrong bolt pattern.

I cut out the centers and made new ones from 1/2 plate and welded them into the rims.

Tubes in all the tires should make for fairly trouble free operation.

 

[Steve Bowman]

Latest big change. The donor valve from the fork truck was far from ideal. It got me by for boom and tilt, but there was no real option for a 3rd function.

I came across a valve assy from a skid steer, which is a whole lot better suited for a loader.

I was able to repurpose the fork truck lever assy. But due to the float detent on the new spool, I had to get creative with the linkage in order to maintain "boom down" by pushing the lever, rather than pulling it back.


Next step is to mount it and plumb it in. This valve is plumbed with -12 and -16 ports and fittings. One of the problems with the fork truck valve is that the ports where only -6 and -8 size. Rather restrictive I think.