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 | JD855inWI
Join Date: Aug 2004 Posts: 38 Mid East Wisconsin 
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2005-10-10 117676
I'm in the middle of converting a fork truck mast to a 3 pt mount on my JD 855. My plan is to take the hydraulic power from the circuit that powers my backhoe. I want to add essentially another joystick for the raise and tilt cylinders, but am concerned about the flow rate. As that circuit has a higher volume pump, do I need to be concerned that all valves and piping have to be sized to handle full flow or will the excess flow past the pressure relief valve? I'm also considering using remote solenoid valves mounted on the mast and a 12V joystick. Anyone ever do anything similar. I built a spliter once that used a 12V valve, a limit switch to reverse direction and a button to start the cycle.
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 | beagle
Join Date: Jan 2004 Posts: 1333 Michigan 
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2005-10-10 117680
If I understand what your circuit will be, it sounds like you will be using a Power Beyond through the valve that you are adding. If that is the case, the new valve should be sized for the full flow rate of the circuit. The pressure relief should not be used for issufficient flow capacity through the valve body, and would build additional heat in the circuit. If you don't size the valve for the full flow, you could damage your pump and have a poorly prerforming circuit downstream from the added valve.
Hope I understood your situation properly. ....
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| JD855inWI
Join Date: Aug 2004 Posts: 38 Mid East Wisconsin
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2005-10-10 117684
beagle: you got it right and thats what I was afraid of. That means things will probably move to fast if the full flow is going to the tilt and lift cylinders. I guess I will have to look at using the power beyond from the loader circuit or install a flow divider. But thats a lot of extra hardware. Option #2 is to drop the loader off and just use the loader valve. Guess I'll just be hanging the weights on the other end of the tractor when I use the fork lift. Thanks for the input. ....
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| beagle
Join Date: Jan 2004 Posts: 1333 Michigan
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2005-10-10 117689
You can control the flow of the work ports without restricting the Power Beyond through the valve body. There are several in line flow restrictors you can use to control the flow through the work circuits. As long as the Power Beyond is free to flow at the pump GPM, restricting the work circuits isn't a problem. The simple way to restrict the flow is to use smaller diameter hoses or quick connects. If you use 1/4" quick connects at the work ports, you have yourself a cheap flow restrictor. Any flow that doesn't go through the work ports will just flow through the Power Beyond without doing any damage ( assuming an open center system ).
There are several flow restictors you can buy that would allow you to set the restriction, but that expense probably isn't necessary for what you are doing. If the work ports are 3/8", or SAE 8, just restrict it down to 1/4" hose. That's what I did for my Top-n-Tilt circuit. Gives me pretty darn good contol over the cylinder movement.
Hope that helps. ....
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| denwood
Join Date: Jul 2004 Posts: 542 Quarryville PA 
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2005-10-10 117704
Are you sure the backhoe circuit has any more flow than the rest of the hydraulics? Backhoes do not need very much flow, the cylinders are very similar in size to a loader although there is only 1 on the hoe where there is typically 2 on the loader for each movement. If your hoe has that much flow, you should be able to hit a baseball out of the park swinging it back and forth. Most of the fork lift cylinders I have seen are larger than similar sized loader lift cylinders. 2 of my neighbors made forklifts for their tractors and used the tractor hydraulics from a full sized tractor and it is just as slow as when it was a forklift and worked great. ....
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| JD855inWI
Join Date: Aug 2004 Posts: 38 Mid East Wisconsin
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2005-10-11 117743
Oh Man: now I guessing. I'm traveling again this week. When I get home next week I'll pull the manuals out and check the specs again. I do remember there was a hydralics package that was installed on the tractor for just the backhoe. The lines are much larger than the lines for the loader circuits. How do the neighbors like using the forklift setups? ....
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| denwood
Join Date: Jul 2004 Posts: 542 Quarryville PA
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2005-10-11 117760
They love them. Both neighbors are Amish and one has it on its own steel wheels like a trailer that attaches to the drawbar, and the other has it on the 3 point hitch. As you can imagine the one with the drawbar mount actually lifts up on the tractor, so with either setup a large tractor is helpful. Another thing to keep in mind it the lift cylinder is single acting so it does not replenish the tractor at all. My neighbor has run dry on high lifts when the tractor was low on hytrans. ....
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 | oneace
Join Date: Mar 2004 Posts: 1490 south central pa
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2005-10-12 117802
I fork lift will have just as much flow as your tractor. The cyl the control tilt and side shift should already have restricting orifices in the ports. In all reality all you would need is an open center valve with as many opt puts that you require. You would have an in port and an out port to plug in to your b-hoe circuit. The tractor will have the relief valve for over load protection. If you wanted to spend the money you could get a valve that has a relief for shock load but is probably not necessary. ....
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| Hettric
Join Date: Mar 2004 Posts: 133 MA
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2005-10-14 117896
JD 855,
I have a 755 and also planned to adapt a forklift mast to the 3pt, after taking the forklift apart, I realised the static weight of the mast,forks,ect. was going to so limit my lifting capacity it may not be succesfull. your 855 has the same 3pt rating of 785# 24" behind link ends ( I have never found out where exactly where this measurement point this is, But the forks alone are 90# each)
I put a hold on the project, time has not allowed me to get back to it, but I also have been thinking along the lines of the "Trailer" mentioned by Denwood, and would love to here more about it. The issue of haveing a CUT that is not heavy enough to hold the "trailer" down can be cured by extending the trailer boom lenth (at the cost of turning radius).
I also noted that the FEL had more capacity, so when time allows I will start with Fork adapter to pin on in place of the bucket.
Good luck, I hope to here more on how you make out. ....
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| denwood
Join Date: Jul 2004 Posts: 542 Quarryville PA
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2005-10-14 117898
That is the same conclusion I came to. I bought the forklift, thinking of possible rear mount and even front mounting on the loader. I gave up on rear mount because I did not feel like there was much capacity left for the 3 point. I had a real fear of breaking it as the 3 point would be raised and the boom would then lift the load, possibly overloading the 3 point. I thought of robbing the carriage for a loader mount. Real forklifts are made to use every day all day. The carriage was made of solid steel, not tube and extremely heavy, heavier than the skid loader versions. I ended up fabricating my own carriage and using just the forks. You can see it in my pics. I sold the complete boom to another Amish man to make a 3 point mount. His tractor is over 80 HP, so it can handle it. ....
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