Backhoe Couple farm questions, backhoe and post driver

[jrchafin]

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!

 

[MtnViewRanch]

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.

 

[powerpace]

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.

 

[bindian]

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.
hugs, Brandi

 

[jrchafin]

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?

 

[LAWALLSTRACTOR]

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.

 

[bindian]

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

 

[MtnViewRanch]

.

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. 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.

 

[MtnViewRanch]

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?

 

[bindian]

If you put one of these in, say next to each of the quick disconnects, you will never fight hydro lock again. 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.
hugs, Brandi

 

[MtnViewRanch]

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.
hugs, Brandi

Brandi, if the hydraulics are hotter than when the hoe was removed, won't there be pressure built up on both sides? Yes you can equalize the pressure, but won't there still be more pressure on the system than when the hoe was removed, thus putting excess pressure on the QDs?

I don't have a removable hoe, so I am not familiar with what works with them and what doesn't, I just know what happens with my grapple and how I have to deal with it.

 

[Redneck in training]

I am not hydraulic expert but it seems to me because of cylinders have unequal volume on each side. If the cylinder is extended (by wiggling valves) it will return less oil than it takes in therefore even small extension might relieve the pressure in the system. If force (in example weight of the machine) causes the cylinder to retract the pressure might increase. Is my thinking correct?

 

[bindian]

Brandi, if the hydraulics are hotter than when the hoe was removed, won't there be pressure built up on both sides? Yes you can equalize the pressure, but won't there still be more pressure on the system than when the hoe was removed, thus putting excess pressure on the QDs?

I don't have a removable hoe, so I am not familiar with what works with them and what doesn't, I just know what happens with my grapple and how I have to deal with it.

Brian,
Usually the hydraulics are warm (especially if using tractor hydraulics) when you remove a BH. The warmth is from running the tractor as you unhook and "walk" the BH off of the subframe. Once you move a control valve on a disconnected BH, the pressure goes to zero. I wiggle the remotes and the BH controls before and after disconnecting and connecting and I haven't had a problem. I wiggle the BH controls after I sit her down on huge blocks (12 inch square and high). But you got me thinking. My 511 BH ops manual shows a placard (decal) that says..........Petcock..open to relieve pressure before connecting fittings. I would have to look on my BH to find it, as the placard is on the control valve cover. I guess the petcock is between the control valve and the quick disconnect.
hugs, Brandi

 

[MtnViewRanch]

Brian,
Usually the hydraulics are warm (especially if using tractor hydraulics) when you remove a BH. The warmth is from running the tractor as you unhook and "walk" the BH off of the subframe. Once you move a control valve on a disconnected BH, the pressure goes to zero. I wiggle the remotes and the BH controls before and after disconnecting and connecting and I haven't had a problem. I wiggle the BH controls after I sit her down on huge blocks (12 inch square and high). But you got me thinking. My 511 BH ops manual shows a placard (decal) that says..........Petcock..open to relieve pressure before connecting fittings. I would have to look on my BH to find it, as the placard is on the control valve cover. I guess the petcock is between the control valve and the quick disconnect.
hugs, Brandi

Brandi, I understand that if the tractor has been used that the fluid is warm if not hot. But lets say that you take the hoe off first thing in the morning, tractor is air temp, say 65 degrees. You use a 3pt implement until mid afternoon. Now the air temp is 95 degrees. All the fluid has warmed up 30 degrees, if not more from the hoe setting in the sun, anyway, it has expanded for sure. Now at this time is there trouble hooking up the QDs? Find that petcock and everybody's problems will be solved.

 

[bindian]

Brandi, I understand that if the tractor has been used that the fluid is warm if not hot. But lets say that you take the hoe off first thing in the morning, tractor is air temp, say 65 degrees. You use a 3pt implement until mid afternoon. Now the air temp is 95 degrees. All the fluid has warmed up 30 degrees, if not more from the hoe setting in the sun, anyway, it has expanded for sure. Now at this time is there trouble hooking up the QDs? Find that petcock and everybody's problems will be solved.

You will still have less pressure on one side or the other of the valve or actuator in the system. Say you don't bled down pressure from the BH when you disconnect. The BH settles down and the temp heats up. Since there was less pressure on one side, it will be the same ratio of pressure when it settles and the sun get hot. So moving a control back and forth will cure that problem. It is the line from the valve to the quick disconnect that would be what the petcock is for. The only way other way is to crack a line or like you said.............install a bleeder and a T to bled it. But that adds a lot of extra cost and a mess when cracking a line at a QD will do the same thing for free. My QDs are a 90 degree type to clear my seat. I am not sure if there is enough room to add a T and bleeder there
hugs, Brandi