Rear arm do not work with power beyond when backhoe is attached.

[meb9796]

I purchased a used backhoe 2 years ago and tore it apart and rebuilt it. I installed a power beyond system on my 3720 about a year ago and it's working fine (ie, I can use the rear arms and loader, etc, just fine). Tonight I connected the backhoe for the first time and filled the tractor with hydraulic fluid as I moved each arm of the backhoe to get it ready to connect to the tractor. Since it wasn't connected, I couldn't really move the arms that much, but each arm is moving fine and I can move the loader while the backhoe is attached, but I can't lift the rear lift arms? They will go down, but will not go back up until I remove the backhoe and reattach the power beyond system. I know that John deere backhoes (this is an ameriequip backhoe that is a 3pt connection) connect to the subframe and you don't need the rear arms, but I know that the power beyond can control a lot more than a backhoe so the rear lift arms have to be able to work while using the power beyond system.

I monitored the hydraulic fluid while working with the backhoe and added over 3 gallons and I know it's a bit low. But when I disconnected the backhoe, the lift arms worked? Anyone have any ideas???

Thanx!

 

[J_J]

Does your BH have PB?

Where is your BH tank line connected?

Do you have a complete flow path from the pump to the tank?

If your BH has PB, your flow path should be like this.

Pump to FEL, to remote, to BH, to 3pt to tank.

PB from each valve goes to the IN port of the next valve.

If your BH does not have PB, your tank line may be going to tank.

If the BH tank line is feeding the 3pt, it would work but not safe.

 

[meb9796]

JJ, thanks for the response. My BH is connected to the power beyond on my tractor. I do have a complete flow path back to the tank thru the backhoe. Not sure if the BH has PB, but everything seems to be working great! I just couldn't get the rear arms to lift the backhoe after I had it attached (the PB to the backhoe). So I quit around 2130 last night and posted my question. I got up early and started doing more searching cause I remembered that JD backhoes are now attached to the subframe, so figured the rear arms wouldn't work. I found a video on you tube showing how to connect a JD backhoe and it confirmed the arms won't work after I connect the BH. So this morning I just set the arms low enough to attach to the bh, then lowered the feet on the BH to stabilize it, disconnected the BH, raised the BH about 1' off the ground with the rear arms, then connected the BH again and raised the feet and put in transport mode and it works great! I have to go to work this morning, so probably won't get to start using it till this weekend. Here is a picture of it when I first got it and it in the barn after I finally got it out of the garage after two years!!

 

[J_J]

Looks good.

Set the BH relief pressure same as the tractor relief valve, or set it higher and then the tractor relief will protect the BH.

Here is a solution to your problem.

A selector valve that will switch the flow from one port to another.

1/2" NPT 20 GPM PRINCE SELECTOR VALVE

You connect the PB supply line into the in port on the two way valve.

Connect the 3pt line to one of the ports, and connect the BH to the other.

Now, just select which function you need.

If you remove the BH, leave the selector in the 3pt position.

 

[meb9796]

Thanks!! That's great!! Just what I wAs looking for.

 

[FredH]

If it attaches to a sub frame , Why would you want to move the 3 point arms ? Your set up sounds similar to my TC30 with the 757 / 758 B.H. . With the B.H. connected , the 3 point arms are disabled from lifting , other wise someone could move the control lever and likely either damag the B.H. or the tractor .

Fred H.

 

[J_J]

He said he had to connect it to the sub frame, and used the lift arms to do it.

Once the BH is mounted, you are correct in that the lift arms are not needed.

You could even remove the lift arms and then it would not matter.

 

[J_J]

JJ, thanks for the response. My BH is connected to the power beyond on my tractor. I do have a complete flow path back to the tank thru the backhoe. Not sure if the BH has PB, but everything seems to be working great! I just couldn't get the rear arms to lift the backhoe after I had it attached (the PB to the backhoe). So I quit around 2130 last night and posted my question. I got up early and started doing more searching cause I remembered that JD backhoes are now attached to the subframe, so figured the rear arms wouldn't work. I found a video on you tube showing how to connect a JD backhoe and it confirmed the arms won't work after I connect the BH. So this morning I just set the arms low enough to attach to the bh, then lowered the feet on the BH to stabilize it, disconnected the BH, raised the BH about 1' off the ground with the rear arms, then connected the BH again and raised the feet and put in transport mode and it works great! I have to go to work this morning, so probably won't get to start using it till this weekend. Here is a picture of it when I first got it and it in the barn after I finally got it out of the garage after two years!!View attachment 430067View attachment 430068

The reason that the 3pt would not work when BH connected is that you removed the supply to the 3pt as it is not needed with a sub-frame BH. The pump flow now passes through the BH valve,then to tank.

The lift will always go down using the lever as you are releasing the fluid in the 3pt cyl, but that is only if the descent knob is turned left to open.

 

[meb9796]

Actually, I don't have the subframe attached yet and not sure I'll be able to get this backhoe attached to the subframe the way it is because the rear cylinders. Going to have a friend come over and fab an adapter to my BH frame so I can attach it to the sub frame. Right now it's sitting on the rear arms, that is why I need them to move, but only when I first connect it and lift it off the ground about a foot then connect the hydraulics for the BH and lower the feet, etc when I get it to where I'm going to use it. Tomorrow I'm going to build a dolly out of extra 4x4's I have laying around to make it easier to get it on and off the tractor and so I can move it when it's off the tractor.

 

[FredH]

Ah , I see . That then would be similar to a 3 point B.H. in a way which , in at least some versions , are very Stiff , with little movement in the 3 point arms due to a fixed top link . Not sure if it would Help in Your Design but When attaching my B.H. , I set the 3 point arms to Basically Dead level , thus they are neither to high or to low , so I don't have to reconnect the lines to move them out of the way , ( Don't Ask How I learned This !! ) :confused3:

Fred H.