Backhoe Couple farm questions, backhoe and post driver

   / Couple farm questions, backhoe and post driver #1  

jrchafin

Silver Member
Joined
Apr 10, 2008
Messages
132
Tractor
Mahinda 7520
Two questions:

1. I use a post driver on my 7520, and it works ok. My problem is that the top link (bar) of the 3PH has play in it, so when I lower the post driver and level (plumb) the ram, everything looks good. However, when I drop the ram, it's inertia actually lifts the driver slightly and makes it strike at an angle, not directly vertical. The play is where the top bar of the 3PH attaches to the tractor, at the draft control. I have the draft lever all the way forward. I compensate by tipping the driver away from the tractor so it strikes vertical when driving. Is there a better way to handle this?

2. Sometimes when hooking up my backhoe, I have a problem getting the hydraulic return line to open. I plug the quick connect in, and it looks good, but when I hit the lever to engage the remote valves, I hear the engine strain under load and I know that the connect isn't opening. I'm pretty sure it always happens on the return line, because I can lift the backhoe with the side-arms, but can't put them back down. If I take the quick connect out and try to push the tip in by hand, it's impossible, as if it's under pressure. I can, however, put it against a flat piece of metal and strike the back of the fitting with a hammer and cause oil to squirt everywhere. I did this today, plugged it back in, and then it worked fine. What's going on here? Is there anything I can do to fix this?

Thanks!
 
   / Couple farm questions, backhoe and post driver #2  
Don't know if this will work, but maybe you could try and see.

1, put the top link in the bottom of the 3 holes, should be less movement I think.
2, get a relief valve so that the line pressure is easy to let off, and hook up is then easy.

Just some ideas that should work, or at least help.
 
   / Couple farm questions, backhoe and post driver #3  
It sounds like you may have too much play in several places. Snug up your stabilizers a bit and check your ram for wear. While your at it check all moving parts for slop. The 3ph adjustment sounds reasonable.
To relieve pressure on you hydraulics just turn your engine off. Hitting a fitting with any object to relieve pressure is a sure way for eye or hand injury.
Possible damage to the fitting each time you hit it is not a good solution to the problem and may create more.
 
   / Couple farm questions, backhoe and post driver #4  
The quick disconnect is not fully locked on. I had one "pop" off half way while tamping and packing a trench, through my dam. I could hoe in the dipperstick and lower the stabilizers, but could not stow anything. I was wiggling so much, it popped off half way and I thought I blew a relief valve and it stuck open. Turn your tractor off, disconnect the quick disconnects, and bleed down all remotes by cycling the levers, along with all levers on the backhoe. After I knew of the problem, it never was a problem again. You might want to consider new quick disconnect fittings if it continues to bother you. I was so dumb founded when it happened to me, I bled the lines and used a hi lift jack and com-a-long to stow the BH and finished filling and packing with the loader and tires to beat the rain that was starting to fall.:eek:
hugs, Brandi
 
   / Couple farm questions, backhoe and post driver
  • Thread Starter
#5  
Thanks all!

Just FYI, I did turn the engine off and I tried cycling the cylinders. Didn't help. I think I will put a new quick connect fitting on.

Mtnview, I've not seen a relief valve in a hydraulic system before. What is it? Where would you put it?
 
   / Couple farm questions, backhoe and post driver #6  
Build a stand to set your backhoe on when not using it. This way there will be no pressure on the backhoe half of the fittings, caused by the backhoe cylinders holding the backhoe up. This way when you cycle all of the levers to relieve pressure, the hoe will set on the stand and have no pressure on the cylinders. I hope this helps.
 
   / Couple farm questions, backhoe and post driver #7  
Galen,
Good idea. Us poor folks used huge blocks of oak to sit under the BH while on the ground. I do whatever I need with the 3PH, then put the BH back on ASAP. I also use dust covers religiously on all disconnected fittings.
hugs, Brandi
 
   / Couple farm questions, backhoe and post driver #8  
.

Mtnview, I've not seen a relief valve in a hydraulic system before. What is it? Where would you put it?

If you put one of these in, say next to each of the quick disconnects, you will never fight hydro lock again.:D Install a tee behind your QD and install the valve so that the main flow, flows right buy the valve. When fluid builds up pressure, (usually from heat) you can now just open the valve and release the pressure that has built up. This typically would only be used when the hoe has been disconnected from the tractor and the lines have built up pressure from the air temperature being higher than it was when you had removed the hoe. Precautions should be taken to keep the exposed end of the valve clean.
 
   / Couple farm questions, backhoe and post driver #9  
Build a stand to set your backhoe on when not using it. This way there will be no pressure on the backhoe half of the fittings, caused by the backhoe cylinders holding the backhoe up. This way when you cycle all of the levers to relieve pressure, the hoe will set on the stand and have no pressure on the cylinders. I hope this helps.

Will you not still have a problem if the air temp is higher than when the hoe was removed?:confused:
 
   / Couple farm questions, backhoe and post driver #10  
If you put one of these in, say next to each of the quick disconnects, you will never fight hydro lock again.:D Install a tee behind your QD and install the valve so that the main flow, flows right buy the valve. When fluid builds up pressure, (usually from heat) you can now just open the valve and release the pressure that has built up. This typically would only be used when the hoe has been disconnected from the tractor and the lines have built up pressure from the air temperature being higher than it was when you had removed the hoe. Precautions should be taken to keep the exposed end of the valve clean.

Either by settling down on the stabilizers and bucket or upon blocks OR temperature changes.........all you have to do is wiggle (bled down) the BH controls before hooking up.:D
hugs, Brandi
 
 
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