What’s this?

   / What’s this? #1  

Quantumkev

Member
Joined
Dec 30, 2022
Messages
31
Tractor
Ford 4500 Industrial Loader/Backhoe
So on my backhoe controls is have 6 levers, that operate 6 valves. I would expect the same mechanical connection between each lever and valve but on the boom connection it is completely different. Can anyone explain what this is, and what it’s purpose is?

Thanks in advance.
 

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   / What’s this? #2  
Is it a Case?
I remember that to store the boom for travel that you'd pull the lever until about the top of its normal stroke, then quickly push it away from you to finish the stroke to the locked transport position.
I've wondered how this magic happens and I still don't know 😆
You mention it's the boom valve and my Case experience came to mind.
 
   / What’s this?
  • Thread Starter
#3  
I should have put it in there originally, sorry for the miss.

This is a 753 backhoe on a ford 4500 industrial tractor.
 
   / What’s this? #4  
I can't help on a Ford hoe, this is mainly for Rusty -

The travel position on a Case hoe is accomplished by a combination of geometry, inertia and a QUICK wrist :rolleyes:

The boom pivot joint cylinder (2 of 'em on older hoes like mine) PULLS in order to raise the boom, until the boom gets ALMOST all the way up - at that point, the linkage goes "over center" - if you have enough momentum at that point, AND you're quick enough to then PUSH on the boom lever, the momentum continues upward travel BECAUSE the boom has passed the over center point, at which time a spring loaded hook (located MAINLY inside the main pivot casting) has engaged the "travel" pin (ALSO located inside the main pivot casting).

The spring loaded hook has a "release" lever, so in order to return to dig you GENTLY push on the boom lever, and as soon as the boom starts to travel further UP, you move that release lever which lifts the hook out of the way, then you PULL the boom lever (which actually LOWERS the boom til it moves past the travel hook - then gravity takes over, and the boom stays UP (but NOT far enough up to re-latch the boom).

The "inertia" part teaches you fairly quickly to NOT bother to try this with the engine at idle - the boom will NEVER have enough momentum to reach that over center position, so if the boom UP travel isn't fast enough, PUSHING on the boom lever will only cause it to go back to DIG position.

Wow, I'd almost forgotten how hard that was to explain - good thing actually DOING it gets to be a habit fairly soon :oops: ... Steve
 
   / What’s this? #5  
Thanks bukit!
I always liked the way they tucked up high and tight. 👍
 
   / What’s this? #6  
Does the boom have float? To me the top gray part looks a lot like the float detent thing you usually see mounted on the hydraulic valve. The yellow thing looks like a damper (ie shock absorber) which would simply prevent you from ‘overcontrolling’ the boom and rattling it up and down real hard. Lots of ‘travel’ levers/pedals have dampers mounted inline with the linkage to take the edge off of rapid inputs.

What the open port on the shock is for, i dont know. If its a single acting cylinder i dont know what it would do there.
 
   / What’s this? #7  
My 6 lever Ford 753 does not have that. I know some of the old Fords had Auto Dig, having never seen one nor understand it, maybe thats what you have.
 
   / What’s this?
  • Thread Starter
#8  
So I really could do with some help on this, if anyone has any idea what it is…. I am trying to move this old backhoe and I had some luck today. One of my hoses is blown, and I thought it was the one for the dipper cylinder, but turns out it is the one for the bucket cylinder. So now I have the old rust bucket running, the loader moving, so I can get the front end in the air for moving the backhoe, and what I thought was a blown hose on my dipper cylinder, meaning I would have to manually move/hoist/rig the back hoe for moving, but now I know it is only the bucket hoses that are bad it is fairly easy for me to chain the bucket in place for moving…… if only I could manipulate the boom cylinder!!!!

With the loader and stabilizers I have 8 valves, and 7 of them work fine. 7 of them operate their respective cylinders (all be it roughly, with leaks etc) so I can manipulate everything into a position for transport, but the 8th valve, the one with this setup on the lever, doesn’t want to do anything….. I know the cylinder isn’t bound, because I manually winched the boom up today, and it moved fairly easily.

I can’t help but think this valves lever setup is what is causing my problem, and if I could understand what/how it is supposed to work I could figure out how to get this cylinder moving too.

Thanks for taking the time to look at this again, and I will take any suggestions!
 
   / What’s this? #9  
Does any portion of the linkage you circled in red move? If the large yellow canister moves and the rod below doesn’t then something in the canister is faulty. You can put a pliers or vice grip on the linkage and operate the valve enough to get home.
 
   / What’s this? #10  
That has to do with the auto-dig function that some of the old ford hoes have.

I have never explored how it operates, nor have ran one that has.

But go to messicks.com........and search for the 753-series backhoe attachment for new holland.

Then start looking at the parts diagram for the control levers with auto dig and you will see those controls.

I also suspect that some of those other unknown valves you were questioning in the other thread might be related to the auto dig function....because there are some diagrams that look pretty similar
 
 
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